Diploma

Checkout the eligibility below:
Diploma (Lateral Entry):
Passed 12th standard / ITI 2 Year Course Approved by NVTI (government of India)
Obtained at least 35% marks at the qualification examination. Tech (1st Year):
Passed 10+2 examination with physics and mathematics as compulsory subject along with one of the chemistry / Biochemistry / Biology / IT/ computer science as subject. Obtained at least 45% marks in PCM (40% marks in PCM in case of candidate belonging to SC/ST) in the above subject taken together. It may vary from college to college.

Admission process varies from institute to institute. You can apply directly to the college or you can also apply online in some of the colleges. Please be specific about the course and the college.

Which university's paper are you asking about?

You will have to inquire and apply for lateral entry schemes in the respective college/university.

Eligibility for Diploma in computer science engineering: A candidate seeking admission in Diploma in Engineering should have passed 10th or High School Examination or its equivalent from an approved Board.

In which course you want to do your Diploma? Just clear this first and nowadays, the major focus is that on computer science, biotechnology, etc. You just go through as per your interest. Rest explore and then ask question if having any doubt.
All the best.