Pimpri Chinchwad Polytechnic

As per the past years' trend, 10th marks above 70% are good enough for this college for Diploma in Automobile Engineering for general category candidates.

You just see the above answer then you try for this college,if answer missed I will tell you in detail. I am a inter candidate who written the ceee in my time and got a rank joined in private engineering college Bapatla now your question answer is later entry, you just complete the vocational inter you may join in polytechnic 2nd year in any branch, 2nd answer is if you complete polytechnic course and written the ECet exam you must took the Btech 2nd year if you got good rank in Ecet entrance OK

It is necessary, but not compulsory. You won't get the 20 Marks Internal for each subject via the PCP teachers then. But, you should go once and get yourself registered for PCP. Then you can share your limitations not to come.
The PCP classes to be true have not been attended by all but the Admit Cards do go to everyone.
So, better you decide to attend and participate in Learning to prepare for exams or start preparing yourself. Once you visit then you get help from teachers and see some classmates as well who can share things.

Without doing the Registration of the PCP, it is not possible to get the Roll Number Admit Cards. Once you have to come and mark your Registration for the PCP through the Distance Education Department or the venue of the PCP.
Realistically speaking, you loose the internal assessment out of 20. I mean they will give you marks based on an average of Theory/Written Parler Marks or via any other mean, but the Internal Assessment you can get in PCP.
It is not compulsory to attend classes. You can go and share your limitations and can see if you attend only a few.

I think it is a very low percentage. You can't get this college but you should try though.

Eligibility for doing Diploma in mechanical engineering is that candidate must have passed 10th standard or its equivalent with at least 35% aggregate marks.
Candidates passing 10th standard from Maharashtra State Board must have Maths/Mathematics (Code 71) and Science & Technology (Code 72) as compulsory subject.
For more information about this diploma visit
https://www.shiksha.com/engineering/course/diploma-in-mechanical-engineering-pimpri-chinchwad-polytechnic-akurdi-pune-232391
Hope it helps you well.

Lateral entry is provided in other states also. You can apply for admission.
Good luck.