do you know anything about the 12 questions after the completion of bitsat exam that is like what are marks alloted for each question , the negative marking,etc....????

You better do one thing, download sample papers and previous years test papers from google/weblinks of the institutions, this will help you get an idea of the type of questions being asked plus whether there may or may not be negative marking, there are some reputed institutions like –  Ambalika Institute of Management and TechnologyLucknow,..............Lovely Professional University, Phagwara,..........RNB Global Universityy, Bikaner,..........Presidency University, Bangalore.... where you may seek admission for your bright future.