If a person becomes kafir, his nikah is broken. How many times is this allowed? For example, if a person performs nikah and becomes kafir, and this happens three times, can he perform his nikah the 4th time?
Answer:
In the name of Allah, the most Beneficent, the most Merciful.
With regards to your question it is advisable that one takes precaution when it comes to doing takfir and also when considering a Muslim to be a disbeliever. It is narrated by Saaiduna Abu Hurairah 
that the Prophet of Allah 
has said, “When a person says to his brother, ‘O disbeliever!’ then disbelief returns to one of the two of them.” (Sahih Bukhari)
You should contact your local Imam or alternatively you can email me wha actions did that person do which makes you or him think that he had one out of the fold of Islam.
If in reality the individual in question has gone out of the fold of Islam then he will have to re-do his Nikah again, irrespective whether it has been up to four times or not. (Raddul Muhtar p.367 v.4 & Fatawa Hindiyyah p.362 v.1)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham