CBSE 10th

Well, firstly you should shift to CBSE, if you want to score a great percentage in your class 12th. Then, depending upon your interest, and future plans you can take either Science or commerce or humanities.

Work hard. Go through the subject matter thoroughly, and practice as many question papers as you can. Make sure you go through the previous year question papers. Above all prepare well, you can definitely get success.

Hi Siddhesh,
After class 10th, one is only eligible for Diploma courses. It is advisable to pursue your 10+2 and then opt for other courses. https://www.shiksha.com/mass-communication-media/journalism/articles/your-career-as-radio-jockey-video-jockey-blogId-4620.

To Target SP Jain College, your score must be above 97 percentile at least if your college is not IIT NIT. They won't call below that unless your profile is exciting for them.

Hello,
Your class 10th and 12 grades are not good, so you have to perform very well in the competitive exams like CAT, XAT, etc., and you should have a valid point of view for low grades in class 10th and 12th.

Speaking frankly, I am doing my MBA and went through the same phase. There is no chance that you get into IIMs if you are from general category. Their first criteria is 90+ in academics and graduation. Over it, you have to score 97-99 percentile in CAT. You can get any other good college if you don't make to IIMs, what matters the most is things you learn in those 2 years.

The minimum eligibility requirement for admission into D.T.Ed course is that the candidate should have passed class 12th examination from a recognized board.

Yes, you can apply as the eligibility criteria is 55% in graduation. For more details, visit below Shiksha link
https://www.shiksha.com/engineering/course/graduate-marine-engineer-the-great-eastern-institute-of-maritime-studies-Lonavla-Pune-29782
Hope this helps you. Be free to share any problem if you have. Good luck!