o not worry.  if it was made in a fit of anger and if you have deleted your comment then no case would be filed against you.

Therefore, do not panic. This is not a serious offence even if any complaint is lodged with police.

In future do not involve God in personal enmity with other. He is ONE and SUPREME among persons of all religions. 

You should lie low and take a leave from the social media for a few days. Don't di anything but wait.

Don't show your presence anywhere on the social media.

This should subside in a few days.

1) if any FIR has been filed against you then police would issue you notice to record your statement 

2) wait for notice to be served 

3) contact a local lawyer 

Dear sir/ma'am,

If the person would have complaint, you would have received a notice or the police would have contacted you.

Since the person started it, you can file a cybercrime case by going to the online portal.

however this is not a serious issue in India so far as cyber law is itself emerging and flourishing.

ADVICES:

1. file a cyber crime case  through online portal regarding this to be on a safer side. this will act as a prove that you were a victim too.

2. keep all the online data/chats and do not delete them. you can take the screen shots and keep them as well.

3. you can even ask the person to send you the proof of that complaint, if not you can send the complaint number of yours to him. you can tell them that you are also a victim since he/she started it first.

4. MOST IMPORTANTLY: try avoiding such situation in future. i know the online platform can be toxic, but try to avoid it.

You stop apologizing with Y or any other person in this regard anymore.

If at all there is any complaint pending with the police, you would have been contacted by the police so far.

Since there is no call or notice from police till this date, it appears that those persons have simply threatened you with a complaint but they have not lodged any complaint.  

Libel in sudden provocation/heat of the moment doesn't attract punishment as in that of grave offence. The spread of message that you have posted is material here. If you approached defaming this X in public then only X can lodge complaint. Y complaining for X without being in capacity of guardian, the complaint would not stand in law. Even otherwise, in  your case  whatever content of the complaint may be it can only be a private complaint under 156(3) of CrPC and not an FIR.

You are advised only to wait with calm and preserve the text messages. If Police approaches you to give your statement, please give them the statement and say that you are ready to apologise and settle the matter. Let that be noted down in your statement before the police authorities. 

Your act may be objectionable as it hurts the religious sentiments of the individual which is his fundamental rights too. But such actions are measured on the basis of their gravity and malice. Kindly be calm and respond to the police authorities  with active presence of mind without being afraid.  

Keep call and message records intact with you. if possible keep hard copies of the same too. 

Most importantly do not get stressed and speak out anything against yourself. 

Hi, Don't worry nothing will happen. You will inform to the police you have written the same out of anger. I don't think it is a fit case to register the FIR.

- There is no reason to take the issue as serious , as you have already apologised for the same to Mr X. 

- However, you may send a written letter/notice to him after narrating the fact that you are ready to apologise for the mistake , which was done due to their remarks. 

- Further, even if Mr X files a compliant , then the police will seek your explanation ,where you can submit the said notice for your safety.