Hello Dear

Since as you said you have obtained 56% overall in your respective Class 12th boards and inoder to apply for the B.Tech in the Government or either Private Institution you should have the atleast score of more than 60% in the class 12th from any of the State or either State Government board and Inorder to apply for with the Management seats in the private institutions you have to talk directly either with the management of that College / University about the donation because in such cases if you go via broker then it might be somewhat heavier for you. So depending upon that you should talk with them.

All the best