How to get a birth certificate of my child who was born outside wedlock

Hi

I am an Indian citizen girl, I was living with a Pakistani guy when I got pregnant and we decided to marry.

I wanted court marriage since I am a Hindu and he is Muslim but he wanted nikah and later will do court marriage also.

So last April he called some people from Karachi online video, I don't know who they were, and asked me for nikah. I said yes and then they said papers would be sent via courier to sign.

After two days of this online thing, only he physically hit me and abused me so badly that I called the police also, but in front of the police finally he said sorry and I also let it go.

After that, I never signed those papers and thought to watch his behavior which later turned bad day by day. Even financially also he was using my house, my car, my everything...

Now this November I'm blessed with a baby boy and I want an Indian passport for him, but this man is now creating problems.

Please help me get the birth certificate of the child.