College of Engineering, Pune

MHCET is the qualifying exam. So, clearing minimum cutoff for boards and your main focus must be scoring MHCET. There is no link between boards and any competitive exam. So, focus on it.

You need to have minimum 60% in Diploma to be eligible for admission in engineering in COEP through lateral entry. Diploma Percentage to get into COEP is subject to number of students appearing for counselling and the cutoff set by the college
https://www.shiksha.com/b-tech/course/b-tech-lateral-entry-college-of-engineering-Pune-shivaji-Nagar-204728.

Yes, with these marks, you will easily get CS there.

All aspirants who have passed / appeared in the qualifying examination i.e. HSC/12th Standard examination or its equivalent examination and having Indian Nationality are eligible for appearing for MHTCET. There is no age limit for admission and appearing to MHTCET. Please refer to the link provided below for detailed eligibility criteria to appear for the MH-CET:
https://www.shiksha.com/b-tech/exams/mhcet.

70% marks in pcm

The last year cutoff was 49 and it may be increased this year.