Dear Shrinjoy 

Yes, you can definitely sit for both JOSAA and NEET (2019) as both are different from each other.However, there are many points to be kept in mind , some of them are mentioned below. They are:-

1. You should be clear enough about the career you are going towards.

2. There should be no clashing of dates and you should able to manage.

3. If you are deciding on the basis of marks and good colleges and getting them through NEET2019 then you may go to medical college.

4. If you are ready to give your life to studies, then go for medical as doctors require a lot of degrees to maintain and succeed in their profession which is very tough / if not then go for engineering(will also require dedication).

5. If you can imagine yourself waking up in the middle of night for treating patients(shifts) and are helpful to the core of heart, go for medical / if not go for engineering.

6. If you are going for private college then its not worth as it is costlier than engineering colleges.

NOTE: The decision is up to you and you are the only one responsible for any decision and as per the above points,they may differ from person to person.

Best of luck.