I want to joined Indian military academy.i am 20 year old.please tell me what type of study and in which way i have to do.

u hav 2 prepare 4 NDA exams Physical standards: Candidate must be physically fit according to the physical standards for admission to National Defence Academy and Naval Academy Examination (II), 2011 as given in appendix-V of commissions notice for the examination published in employment news/rozgar

To join IMA you have to clear CDS Examination conduct by UPSC. for this you must be Graduate.