Class 12-science

First of all the depends on your inclination of your hobby. since you have done 12th with science ,then you have a wide options of career to explore for you can do b.b.a(bachelor of business administration) or B.A(bachelor of arts) and you can also prepare for U.P.S.C. so there are number of options but the questions depends upon you. choose that career in which you have inclination best of luck

You can go for amity Noida for BCA plus MCA. You can also go for IP university if you appeared for entrance exam

You must plan your education upto minimum MBA. MBA Marketing from top 5 colleges in India is first step to be a CEO after few years of experience. Remaing path to top is your hard work , leadership qualities and above it your destiny. There is no guranteed path to success.

First of all u should do btech.
N if u have a strong will 2 b an IITian. then why should u wait for Mtech.
Do it know . Take drop n perform well in jee advanced. n also give improvement of class 12th.

Really it depends on your interest. Never choose branch in hurry. Choose it wisely and #according to your interest