Class 12-science

PCM because this would be light and you can focus more on the entrance stuffs rather than banging your head again for biology.

According to me, it is better to do B.Tech from a reputed government college because government college has more value than the private college.

Yes, you are eligible to pursue B.Sc Forestry from Guru Ghasidas Vishwavidhyalaya. The minimum criteria to apply is a score of 50% in class 12th with mandatory subjects: Biology, Agriculture and Maths.
Age-Maximum 22 years
Admission Process
Admission is through counselling based on the rank obtained in Vishwavidyalaya Entrance Test (VET).

If you are passionate about computer science, there is nothing better than CS but you have to work hard for getting CSE in a prestigious college.
Good luck!

No! Lateral entry is the admission process for diploma holder students for admission directly in the second year. You have to give an entrance exam.

Eligibility for B.Sc. In Agriculture:
Interested aspirants for the course are required to fulfill the below-mentioned eligibility criteria:
Completion of Intermediate (12 years of school education) in Science stream
Physics, Chemistry, Biology and/or Mathematics as the subjects of study
Since you have cleared class 12 with PCM as your main subjects, you are eligible to apply for admission to B.Sc. Agriculture.
Regards.

Top automobile engineering colleges in India where you can pursue automotive engineering after completing class 12 is mentioned at the link provided below.
The ranking is based on engineering ranking 2015 published by The Week.
https://www.shiksha.com/b-tech/ranking/top-automobile-engineering-colleges-in-india/51-2-0-0-0.

I will strongly recommend you to take computer subject in 12th, this will help you in computer Science engineering after 12. You can give various engineering entrance exams including JEE Mains and JEE Advanced.

Hi Rupesh,
There are many competitive exams after 12th non medical, which exam you can take will depend on your desired programme of study and your stream and subjects you studied. Popular ones include
JEE Main Entrance ExamBITSAT 2017 Entrance ExamDelhi University Entrance Exams After 12th Science PCMUUEE Entrance ExamPondicherry University Entrance ExamAMU Entrance Exam ICAR AIEEA Entrance ExamKIITEE Entrance ExamUPESEAT Entrance ExamMU OET Entrance ExamBVP CET Entrance ExamSAAT Entrance ExamAllahabad University Entrance ExamsSymbiosis Entrance Test (SET).