And also I belongs from ST Category 

Of course there would be some reservation for ST , but not much. Most preference is given to state board students. If you fit into both reservations you can surely get addmission easily. 

Thank you!

I have 54 % in 12th and  and 33 % in pcm and 108 in nata can I get admission in b.arch please help me 

Hello Sachin ,I request you to post your questions separately from next time , it will be helpful to answer to your condition personally. Anyway , as most architecture colleges require 50 % marks in your 12th grade and a valid score in NATA , you can get addmission in B- grade colleges. Like the ones which are not top ranked because they require a higher score in both. You should try for new emerging universities as they are new they might not be top ranked but will consider your addmission with this score and have a good faculty too. If you are from state board , you should apply to the colleges of your state first , they have some 50% reservation for state board students. Also if you are from SC/ST/OBC , you will have the advantage of reservation there too. Hope this information was useful. All the very best.