Hello B Lalitha, If you got 99.6 percentile in JEE Main paper 1 then your all india rank will be around 5 thousand after JEE Main April. your EWS rank will be around 600.As you are a female EWS Candidate so you will get admission in most of NIT's but branch will differ from NIT to NIT.

Last year closing all india rank cutoff for NIT Trichy for female EWS

Electronics and Communication Engineering 4735

Instrumentation and Control Engineering 27868

Mechanical Engineering 15650

Metallurgical and Materials Engineering 29970

Production Engineering 24310

Chemical Engineering 13582

Civil Engineering 29421

Computer Science and Engineering 3234

So, you can see that as EWS Female candidate you can get admission in most of the branches in NIT  Trichy, and NIT Trichy is amongst the top NIT.