Dear Friend, your score in almost all the subjects is quite good, so there is no need for improvement and for your preparation, you may follow these tips –stay focused and get to know the loopholes where you need to work a lot, like you said that you are weak in mathematics. Divide your hours for an individual subject and pay due attention to that subject in order to fortify your PCM, join a leading academy/coaching center for preparation; download sample papers and previous test papers followed by answer key to understand the pattern of the questions; make yourself undergo a strenuous practice session and follow NCERT books as base books; try to locate some hihgly reputed institutions where you may rest assured about a guaranteed bright futute, like – RNB Global University, Bikaner,........................CMR Technical Campus, Hyderabad,.....................Lovely Professional University, Phagwara,.................Galaxy Global Group of Institutions, Ambala