Infotix -- A Technology notepad

First of all choose the right institute for your preparation as most of us need coaching (exceptions are always there).You can choose between Narayana ,Fiitjee, Brilliant,Pie, Vidyamandir Classes but the important point is how well you are dedicated to your insti as this a matter for 2 years.
And remember one point what matter is you and your hardwork ,institute plays a very little role.More or less all the institutes are same.
Secondly,be very sure that initially you got the good batch i.e. among the top batches.
Since preparation for engg. is for almost 2 years many a times ,students can't cope with it,
so be sure that you are fully devoted to it.In the mean time don't worry about the drop in percentage in school(if it happens) as the percentage doesn't play any significant role in your selection except a minimum criteria of 60% in IIT,AIEEE,DCE/NSIT and 80%(PCM) in BITS.
I think there are various points that you should keep in mind while your preparation.
Some of them are as follows:
1)Don't join any kind of test series or private tuition(for board studies) other than your institute.
2)Keep full faith in your institute and teachers.Do whatever they say
3)Analyse all the test and your score and try to keep the score almost constant or with little
increment every time.
4)Don't compare marks with your classmates or friends.
5)Always maintain your composure,be humble and respect your teachers.

While writing this i have shared my experience while preparing for engg from Vidyamandir,so my views can be can be exactly or nearly in random with many of the people,Therefore it is upto you to decide.So,best of luck for the long journey ahead of you and for you future too.