Hi aspirant

There are several colleges  you can get.As you have scored 40K rank its really good .Based on your rank you can get NITs.

NIT Silchar->Civil Engineering  (If you are home state candidate of Assam you'll get any of the streams)

NIT Sikkim ->Civil Engineering/Electrical and Electronics/Mechanical Engineering

NIT Manipur->Civil Engineering/Electrical Engineering

To participate in counselling and seat allotment of JEE Main 2019 candidates will have to register to JoSAA in online mode.

The counselling and seat allotment of JEE Main 2019 will be based on candidate’s merit, preference of choices and availability of seats. During the JEE Main 2019 seat allotment, JoSAA will first allot the seats in two mock rounds. You must apply for it.

You can check the cut offs of other NITs:https://engineering.careers360.com/articles/jee-main-cutoff

All the best.