Lateral entry

Yes dear. You will get admission there if they are providing lateral entry. Although you scored a good percentage. Kindly visit their official website.

Yes, you can do B.Tech in CSE through lateral entry.
BITS Pilani
IIT-Delhi
National Institute of Technology, Karnataka
VIT University, etc.

Indian Maritime University (IMU) conducts IMU-CET (Common Entrance Test) for admissions various programmes offered by IMU campuses.
For more details, please refer to:
https://www.shiksha.com/university/indian-maritime-university-chennai/imucet-exam

Dear,
There are several colleges but I will tell you to choose the best such as LPU, SRM, VIT and Bennett University.

Yes, anyway The weightage of 12th standard's percentage matters the most. A minimum of 50% is a must.

You need to appear for IMUCET.
Interested candidates can apply online/ offline with required information. Candidate has to appear for the IMUCET (Indian Maritime University Common Entrance Test). Link:https://www.shiksha.com/b-tech/course/b-tech-in-marine-engineering-lateral-entry-himt-college-kilpauk-chennai-268542

Eligibility Criteria for admission :
Age : Maximum 32 years
Candidate must have passed Diploma in Engineering/ Technology or B.Sc. in Mathematics from a recognized board or university with minimum 49.5 % marks (44.5% for reserved category).
Maximum age for reserved category or female candidate is 35 years.

Yes, you are eligible. Eligibility for BE (Lateral Entry ) -
Candidate must have passed Diploma in Engineering/ Technology or B.Sc. From a recognised university.