He forgot to do tawaaf al-ifaadah and he went back to his homeland and could not return to Makkah
Question

                My maternal uncle is an old man who is advanced in years and blind. He went for Hajj 4 years ago and forgot to do tawaaf al-ifaadah and was unable to do tawaaf al-wadaa’. What does he have to do to make his Hajj complete? Is it permissible for him to delegate someone to make up the tawaaf on his behalf?.
Praise be to Allah.Firstly: 
Tawaaf al-ifaadah is one of 
    the pillars or essential parts of Hajj, and the pilgrim cannot exit the 
    final stage of ihraam except by doing it. Based on that, your uncle is still 
    in ihraam so several things are required in his case: 
1 – He must refrain from 
    intercourse until he has done tawaaf al-ifaadah and exited the final stage 
    of ihraam. If he had intercourse when he did not know that he was still in 
    ihraam, he does not have to do anything, but he must refrain from 
    intercourse from now on. 
2 – He must go to Makkah 
    and do tawaaf al-ifaadah. It is mustahabb to go to Makkah for ‘umrah, then 
    when he has finished ‘umrah and shortened his hair, he should do tawaaf 
    al-ifaadah. This is so that he will not enter Makkah without ihraam. 
See: Majmoo’ Fataawa Ibn 
    ‘Uthaymeen (23/194). 
3 – With regard to tawaaf 
    al-wadaa’, if he does tawaaf al-ifaadah and leaves Makkah immediately after 
    that, this tawaaf will suffice for both tawaaf al-ifaadah and tawaaf 
    al-wadaa’. 
Secondly: 
It is not permissible for 
    him to appoint someone to do tawaaf on his behalf, because tawaaf is a 
    pillar of Hajj and is not a matter for which one can appoint a deputy.  
But if he is unable to go 
    to Makkah, because of sickness or because he is financially unable, then 
    some of the scholars regard him as coming under the same heading as one who 
    is prevented from proceeding with Hajj. So he should slaughter a sheep where 
    he is and distribute its meat to the poor and needy. Thus he will exit 
    ihraam and will not have to do anything more after that. But if this was the 
    obligatory Hajj of Islam, then he still has to do it, because this Hajj was 
    not completed. Whenever he becomes able to do Hajj, it is obligatory for 
    him. 
Al-Ramli said in his 
    commentary on Asna al-Mataalib (1/527): From the concept of the one 
    who is prevented from proceeding with Hajj, al-Buqayli deduced that if a 
    menstruating woman did not do tawaaf al-ifaadah, and she could not stay 
    there until she becomes pure, and she went back to her homeland when she was 
    still in ihraam and did not have any money and could not go back to the 
    Ka’bah, then she is like one who has been prevented from proceeding with 
    Hajj, so she should exit ihraam by means of making the intention, offering a 
    sacrifice and cutting her hair. End quote. 
Something similar is said 
    in Mughni al-Muhtaaj (2/314) and Nihaayat al-Muhtaaj (3/317). 
And Allaah knows best.