Yes you can apply for nit 

You will surely get a seat in nit 

Your advanced rank is not required

You can get cse in nit Puducherry and nit Silchar 

Also u can get ece or mechanical ,civil in nit Patna or nit Durgapur or Hamirpur or Jamshedpur

You can get good course in many nits 

Don't worry about it

U can get cse in IIITs through josaa counselling

To be very clear, your admission to NITs is solely done on the basis of your JEE MAIN rank hence if you even didn't qualify JEE Advanced you would still get admission based on JEE MAIN rank.

Your rank of 18323 is good enough to get to seats in several NITs depending upon the branch which you choose to take. The only decision to be taken is whether you will prefer branch or college!