Colleges in Rajasthan

Yes, definitely percentile matters. In fact, admission is done on the basis of the percentile and interview is just a formality. Once you receive the letter from Banasthali it means you are selected.

No, not at all. It's totally based on concepts. If you had studied in class 10th and 12th sincerely, you will be easily able to crack the exam.

I don't think so because your graduation will get completed in August and admissions start from March and are closed in June. And it will be compulsory for you to attach your result because university select students on the basis of the percentage too.

For taking admission in B.Sc course, you don't have to give any exam. It totally depends on your class 12th percentage. Even you won't have to give an interview. Just fill the form online and if you are selected, they will call you for further process. So, don't worry.
Good luck.

yes, you can apply for the course part time or you can do the same in distance education.
good luck

All of the 3 colleges which you mentioned are the technical institutes providing best of the technical exposure to there students and know-how. These institutes does have management programs but are average in providing you with any good management skills and exposure. They will give you placement but the company might not be of your core MBA specialisation (Marketing, HR, Finance etc. ). So in my opinion opt for a good Business School for the MBA course.

JK Lakshmipat University does not provide an integrated B.Tech and MBA degree. However, the B.Tech programme at JK Lakshmipat University is a redefined programme in line with the innovative and future-ready technologies running the world. With a multidisciplinary pedagogy designed by the #3 in the US, Olin College of Engineering, JK Lakshmipat University focuses on project-based learning. With the current internships and placements in organisations like BARC, Bonn, Airports Authority of India, Paytm, and more, B.Tech from JKLU opens a sea of opportunities to students in their desired domain.

You can take there entrance or can apply through JEE Mains. If you perform well in this then you can get admission in BITS. Good luck.

BITS Pilani is one of the premier institute of India. If you want to pursue your Masters from BITS then your decision won't go wrong. Placement is good enough. You will even get a tag name of BITS Pilani which matters a lot. All the best. Placement is good for mechanical too.