Sorry Jeevan 

But what you are saying is impossible. How can you get a seat in NIT Calicut , with such a low rank. 

You are saying that you have 25668 category rank (obc-ncl) and yet you want to go to nit Calicut. 

This won't happen. You should probably go for some lower NIT's or lower IIIT's . There you might get a seat. That also is not confirmed. 

Why don't you visit josaa website and see previous year closing rank for different colleges. You might get an idea what you have to do. 

Hope it helps.

Thank you