When To Say Du`a For Breaking Fast
Question

The fasting person will have his prayer answered when he breaks his fast, so when should he make du`a – before, during or after breaking the fast? Are there any du`as which were narrated from the Prophet (peace and blessings of Allah be upon him) or that you can recommend for this time?
Praise be to Allah.This question was put to Shaykh Muhammad ibn ‘Uthaymin (may Allah have mercy on him), who said: 
“Du`a should be made before iftar (breaking the fast) , at Maghrib , because this combines weakness and humility, and because he is still fasting. All of these are means of having one’s du`a answered. After breaking the fast, one is relaxed and happy, and may become negligent. But there is a hadith from the Prophet (peace and blessings of Allah be upon him) which, if it is sahih, shows that the du`a may be made after breaking the fast. It said: ‘Thirst has gone, the veins are moist, and the reward is assured, if Allah wills.” (Narrated by Abu Dawud; classed as hasan by al-Albani in Sahih Sunan Abi Dawud, 2066). This can only mean after breaking the fast. Similarly it was narrated that some of the Companions said: “O Allah, for You I have fasted and with Your provision I have broken my fast.” 
So you may pray to Allah and say whatever du`a you think is suitable .
For more, please see this answer: 65955
And Allah knows best.