Yes, you can prepare for JEE. You have enough time for your preparation but most important thing is determination and self motivation. You should be confident to crack your exam.

In order to be eligible for NITs/IITs/IIITs and CFTIs make sure you get 75% marks in your 12th class boards or you should be in top 20 percentile. For ST/SC you should have 65% marks.

To start your preparation you can take help of NCERT books. So, that you can build your base strong. You can also make your time-table. So, that you ca complete your syllabus on time and you get enough time for revision. Always choose a right study material for your study. Don't run after many books. You can take help of previous year papers to know the exam pattern and level of questions. Practice plays a very important role in scoring good marks and to increase your speed during exam. You should solve complete mock test series to analyze your preparation level at regular interval of time. It is very important to do complete analysis of your mock test series. So, that you can learn from your mistakes. Knowing your strength and weakness and regularly working on that is very important.

Revision plays very important role make sure you give proper time to revision daily.

All the Best for your Preparation!!