Exam

Yes, you will get admission in a government college with such a rank, but the college you will get would not be very good. It will lack in various aspects as compared to various other NITS or IITs.

The information regarding each and every course provided in the university is available on the university website along with the important dates for admission procedure. www.christuniversity.in

If we consider previous years cut off then you hold chances to get into NIT PATNA or NIT HAMIRPUR. The closing ranks of these colleges for b.arch last year were around 2500. You can try for your home state NIT as well, that will double your chances to get a seat there. Else there are other colleges

You can sit for the exam but you cannot be a part of the NIT's counselling as you do not fulfill the eligibility of having more than 75% in your 12th class.

IIITs-270-290
NIT (top5)-250-270
NITs (next 5)-230-250
NITs (rest)-190-230
Others-170+

NIT will not be possible with this score still you can try your luck with home state NIT or some low rank NITs. Else, you can go for some GFTIs or regional engineering colleges and you might get a seat in one of those.

Class 11th score doesn't matter at all. All that matters is 12th percentage. You will have to score more than 75% for eligibility. So, don't worry about 11th score. Study well to score as much as possible in 12th and in JEE exam.
Good luck.

Yes, you can get admission in the college, fill up the application form now.