hello aspirant,

18000 rank would fetch you a obc category rank below 4000,which is a decent rank and you have fair chances to fetch seat in good nits and iiits.below are few colleges where you have chances to fetch seat in for cse:

NIT jalandar

NIT uttarakhand

NIT srinagar

NIT mizoram

NIT manipur

NIT arunachal pradesh

NIT sikkim

NIT raipur

NIT nagaland

NIT agartala.

note that the above colleges you have chances based on admission cutoff of last year cutoff round 6 closing ranks.each year the cutoff chances due to many factors like total studentsappearing for exam,difficulty level of paper etc.so if cutoff chances so are your chances into colleges.

for more information to get a personalised report on what all chances you have for your rank refer to: https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

hope this helps,

thankyou.