What happens if I just passed in JEE mains and got good rank in advance

Of course, so long as you get the required marks to qualify not just for Advanced, but for the seat in the NITs/IIITs.

For example, in 2015, the year I wrote in, the cutoff for qualifying for JEE Advanced was 100-something. But that does not mean scoring that much will mean you're guaranteed a NIT/IIIT seat. The seats for branches in those colleges with have their own cutoffs for their seats, which is almost always higher than the Advanced cutoff for Mains.

Your score will be translated into a rank which will be determine your eligibility for those seats.

You will have lots of option to choose where you want to get admission and in the branch of your choice.

All the very best and good luck.

than you can enter the best institute of INDIA and than you can continue your engineering and work for the betterment of the country.

The institutes are:

• IIT Roorkee. IIT Roorkee. ...
• Forest Research Institute. Forest Research Institute. ...
• Indian Institute of Science. Indian Institute of Science. ...
• NIT Srinagar. NIT Srinagar. ...
• Sikkim Manipal Institute of Technology. Sikkim Manipal Institute of Technology. ...
• IIT Kharagpur. IIT Kharagpur. ...
• BITS Pilani Goa. BITS Pilani Goa. ...
• IIT Bombay. IIT Bombay.