Previous employer hasn't paid ₹64k and is not responding to message and calls.

So , previously I worked at a startup (glideai.in) , and worked on the backend for months and he did not pay me for my last 2 months of work , too much time has passed and still nothing. I was working remotely so only know that he is based in gurugram, don't know the address.

What to do in this case. How to take legal action on him (Sahil Gulati)