Ans: Hello Pritesh,
As of now there is no restriction on the number of attempts for the NEET exams as per NTA.

Ans: As I see, you must be in the 10th std. You need to go to the UPSC site and get info on the NDA written examination. Once you get the syllabus, start putting in at least 2 hours of study for the exam which is held twice a year. Your first attempt will be in Sept of your 11th class year. There are a lot of coaching centre's which train for the exam but be careful while you chose the same. The SSB training can be done once you pass the written for which I can guide you later. Be sure that you do very well in the written as there are limited seats for girls at the academy! All the best Agatha! Look forward to good news of your passing the exam!