When is one counted as having caught up with the prayer in
      jamaa’ah?
Question

                I have some problems regarding prayer in jamaa’ah, and hope that you can answer the following questions: If I join the prayer in the last tashahhud, am I considered to have caught up with the prayer in jamaa’ah or not? If I cannot recite al-Faatihah even once during prayer in jamaa’ah, because the imaam reads too fast or because there is no pause in which I can recite it, is there anything wrong with that?
If I reach the mosque and the iqaamah has already been recited, should I join the jamaa’ah when the iqaamah is recited or when the imaam does rukoo’?
Praise be to Allah.According to the correct view, you can only catch
      up with the prayer in jamaa’ah if you catch up with and do a rak’ah
      with the imaam. Merely catching up with the tashahhud or what comes before
      the tashahhud, but not with the rak’ah, does not count as having caught
      up with the prayer in jamaa’ah. I offer you my condolences for your
      great loss if you have caught up with nothing of the prayer except the
      tashahhud. The evidence (daleel) for this is the hadeeth of Abu Hurayrah
      (may Allaah be pleased with him), who said that the Prophet 
 (peace
      and blessings of Allaah be upon him) said: “Whoever catches up with a
      rak’ah of the prayer has caught up with the prayer.” (Narrated by
      al-Bukhaari in al-Mawaaqeet, Baab man adraka min al-salaah rak’ah,
      580; Muslim, Kitaab al-masaajid, 607).
This is the correct scholarly view; and it is the
      view of Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him), and
      is the view favoured by Shaykh Ibn ‘Uthaymeen (may Allaah preserve him).
      It is the view which is supported and strengthened by the evidence.
With regard to reciting al-Faatihah in the
      prayer, this is one of the most important of the arkaan al-salaah
      (pillars or essential parts of the prayer), and the prayer is not valid
      without it, because the Prophet 
 (peace and blessings of Allaah be
      upon him) said: “There is no salaah for the one who does not recite the
      Opening of the Book.” But if a person is praying with the imaam and
      catches up with him during the rukoo’, for example, and he does rukoo’
      without reciting al-Faatihah, this is OK, and the imaam’s recitation
      will count as his recitation, because of the famous hadeeth of Abu Bakrah
      (may Allaah be pleased with him), “May Allaah increase your keenness,
      but do not do this again.”
But if the imaam is clearly rushing, as you say,
      then the essential element of tranquillity and measured pace is not there
      (such as the prayer of some of the Hanafis), so the prayer offered behind
      him is not valid, because he is not qualified to lead it and because one
      of the essential elements of the prayer – that of a measured pace – is
      lacking. This condition is based on the famous hadeeth about the one who
      did not pray properly. But if it is only the case of the imam reciting
      relatively fast and he is able to maintain the required measured pace, in
      this case it is usually possible to recite Soorat al-Faatihah behind him,
      and if you can recite it faster, there is nothing wrong with that. But if
      you are not reciting al-Faatihah for another reason, such as laziness or
      forgetfulness, or because you joined the prayer late, then this does not
      affect your prayer, which is still valid, and the imaam’s recitation
      counts as your recitation.
The Muslim must hasten to prayer as soon as the
      call is given. This is one of the attributes of the believers whose hearts
      are attached to the mosques. Being late and only coming when the iqaamah
      has been given is a sign of weak faith and little desire to do good and be
      obedient. The Prophet 
 (peace and blessings of Allaah be upon him)
      would be attending to his family’s needs, then when Bilaal gave the call
      to prayer, he would stop what he was doing and rush to pray. He 
      (peace and blessings of Allaah be upon him) used to say, “Let us relax
      with it [the prayer], O Bilaal” and, “My delight has been made in
      prayer.” Whenever something distressed or worried him, he would hasten
      to pray. But those who are lazy and do not come to the mosque until the
      iqaamah has been given or during the prayer or during the tashahhud should
      check and rebuke themselves, for the believer’s deeds will say to him in
      his grave: “By Allaah, I only saw you quick to obey Allaah and slow to
      disobey Him.” But in the case of the munaafiq (hypocrite) and faasiq
      (evildoer), his deeds will say: “By Allaah, I only saw you slow to obey
      Allaah and quick to disobey Him.” (This is a hadeeth narrated by Imaam
      Ahmad. It was classed as saheeh by al-Albaani in Ahkaam al-Janaa’iz,
      where he also mentioned its isnaads).
Allaah described the munaafiqeen (hypocrites) as
      follows (interpretation of the meaning): “And when they stand up for
      al-salaah (the prayer), they stand with laziness” [al-Nisaa’ 4:142].
      So let people pay attention to the seriousness of this matter, and let
      Muslim women too beware of delaying the prayer until the last moments and
      beware of letting worldly concerns distract them from paying attention to
      the provision of the Hereafter… Whoever gets used to praying regularly
      on time with the jamaa’ah in the mosque when the call (adhaan) is given
      will find that this becomes his main concern and will no longer neglect
      it, in sha Allaah. Whoever tries this will find deep joy, tranquillity and
      peace of heart and mind in the prayer. This will enable him to attain the
      proper sense of humility (khushoo’) when he stands before Allaah. One of
      the favours of Allaah to people is when a year goes by and a person never
      misses a single fard prayer with the jamaa’ah, except for a valid
      excuse. The sincere believer gets very upset if one day he sleeps and
      misses the prayer, or is late for the prayer because of some worldly
      matter, and all of the matters of this world are insignificant and
      fleeting. This is one of the ways in which Allaah helped His slaves to
      obey Him and remain steadfast.
If the iqaamah has been given, the worshipper
      must join the jamaa’ah straight away, even in the Fajr prayer and even
      if the imaam is reciting a lengthy passage, because of the hadeeth of Abu
      Hurayrah (may Allaah be pleased with him) who said that the Prophet 
      (peace and blessings of Allaah be upon him) said: “Once the iqaamah for
      the prayer has been given, there is no prayer except the prescribed
      (obligatory) prayer).” (Narrated by Muslim in Kitaab Salaat
      al-Musaafireen, Baab 710). In this case any other prayer is not valid.
      For example, if a person starts a naafil prayer then the iqaamah is given,
      he has to stop his prayer, then make it up, if he wants to, after the
      (fard) prayer. If he completes the (naafil) prayer, it will not count and
      will be invalid.
Some scholars said that if he is nearing the end
      of his naafil prayer, he can complete it if he knows that he will be able
      to catch up with the first Takbeer (Takbeerat al-Ihraam), because the
      point is to hasten to join the imaam in the prayer.
And Allaah knows best.