Hi Gunjan

JEE Main 2019 will be conducted in online mode twice a year now. The exam conducting body has changed from CBSE to National Testing Agency (NTA). 

Students will have three options - to appear in January 2019 attempt or to appear in April 2019 session or to appear in both the attempts. 

The scores of best of the two (if appeared in both the attempts) will be taken into consideration for ranks. If appeared in one, then ranks will be made on the basis of scores obtained in that particular attempt.

The January attempt is to be conducted from January 6 to 20, 2019 in 8 different sittings out of which candidates need to choose one. The application for this attempt will be available from September 1 till September 30.

The second attempt will be conducted in April from April 7 to 21, 2019 in 8 different sittings out of which candidates will have to choose one. The application for this attempt will be available from the first week of February.

You can check more details from the link given below:

JEE Main 2019 

All the best !