Class 12 marks play a very vital role for any entrance examination. In case of technical exams, such as UPSEE the candidates who are giving the examination must have cleared class 12 with a minmum aggregate of 60%, if you are from general category. Class 12 subjects(Physics, Chemistry, Maths) are neccessary as through these only your aggregate % is calculated and the entrance exam of any technical institue is solely based on these subjects.

I hope this answers your query.