Hi vivek,

You are good range of gate marks maybe you will get better IIT/NIT. 

Also i am giving you a link of career 360 college and PSU's predicter.hope this link will help you to predict your college and PSU's.

https://engineering.careers360.com/gate-college-predictor

you have to fill basic detail in it then you can see your college and psu's chances.

Apart from this i would like to tell you the top 10 IIT and NIT college.

1.Indian Institute of Technology Bombay 

2.Indian Institute of Technology Delhi

3.Indian Institute of Technology Kanpur

4.Indian Institute of Technology Madras

5.Indian Institute of Technology Roorkee

6.Indian Institute of Technology Kharagpur

7.Indian Institute of Technology Jodhpur

8.Indian Institute of Technology Mandi

9.Indian Institute of Technology BHU

10.Indian Institute of Technology Jammu

here the some NIT'S

1.National Institute of Technology Tirchy

2.National Institute of Technology Warangal

3.National Institute of Technology Calicut 

4.National Institute of Technology Allahabad

5.National Institute of Technology Jaipur

6.National Institute of Technology Bhopal

7.National Institute of Technology Kurushetra

8.National Institute of Technology Jhalandhar

9.National Institute of Technology Hamirpur

10.National Institute of Technology Uttarakhand

hope it will help you.