Which date should I report to the alloted IIT 2019 for further admission process?

Yes, your son can easily appear for ongoing JoSAA 2026 counselling and the choice-filling process. However, to get a seat on IIT, your son must score 75% aggregate in the 12^th CBSE for the general category, and for SC/ST/PwD, the score must be 65%.

Yes, you have a chance to get admission mostly in newer IITs with a General EWS rank of 3500 in JEE. 

If a student wants to join the IIT Roorkee BTech or BSc programme, then appearing for JEE Advanced is mandatory. Students have to clear the JEE Advanced cutoff and participate in counselling to get a seat. However, for any non-BTech/ BSc programme, JEE Advanced is not required. Students may submit a

If you belong to the General AI category, the JEE Advanced cutoff rank required for B.Tech. in Mathematics and Computing was 856. Similarly, for B.Sc. (Research) specialisations, the cutoff rank required for admission in 2025 was 2263. 

On the JEE Main result, candidates can check if they have qualified for the JEE Advanced exam.