Birla Institute of Technology, Mesra

Hi Vikash,
Yes, from last two years BIT Mesra conducts spot counselling and for sure you will get good branch. Go for it.
Thank you and keep asking.

Admissions in BIT Mesra, are taken on the basis of JEE mains AIRs. If you have a rank that is within the cutoffs of the required ranks, you can then take admission in the college. For that, you have to fill up BIT as your choice and also the branch you want to take admission in, during the online counselling. If you get a seat in BIT, then you have to go to the college campus in Ranchi, to do the formalities with all the needed documents. The list of documents and the papers needed will be displayed on the BIT official website- bitmesra.ac.in .
After reaching campus you will be directed by the college staffs to do as needed.

The admission procedure for an OBC candidate is as same as any other student at BIT mesra, except one thing. An OBC candidate has to produce a certificate clearly stating that he/she belongs to OBC category whenever and wherever asked. Also an OBC candidate has an opportunity of getting scholarship, once taken admission in the college.

Don't know about Sindri much but as far as Mesra is concerned, there is no admission through lateral entry, to grab a seat in Mesra one has 2 go for JEE Mains

You can get it from college pravesh website.

Here is Birla Institute of Technology, Mesra's previous year's cutoff for architecture:
Five-Year B.Arch. CourseHS Architecture - 2648 6481
OS Architecture - 1077 3407

Yes, you will definitely get admission in BIT, Mesra, because you have cleared JEE Mains required cutoff and you belong to OBC category.
So, don't worry. You will get a seat into BIT, Mesra.

Sorry to say but it is difficult for you to get admission with this score in an architecture college because above 90 marks are required in NATA to get admission for B.Arch in various government colleges. Also, for NITs and government colleges you need above 300 marks in JEE paper 2.