Hello Siddharth, 

With 30,238 rank in JEE mains you might get following NITs, IIITs with CSE, ECE or IT:

• Indian Institute of Information Technology Guwahati, Guwahati, Assam
• Indian Institute of Information Technology Manipur, Heingang, Manipur
• Indian Institute of Information Technology Surat, Surat, Gujarat
• Indian Institute of Information Technology(IIIT) Dharwad, Dharwad, Karnataka
• Indian Institute of Information Technology(IIIT) Kalyani, West Bengal, Kalyani, West Bengal
• Indian Institute of Information Technology(IIIT) Kilohrad, Sonepat, Haryana, Sonipat, Haryana
• Indian Institute of Information Technology(IIIT) Kottayam, Kottayam, Kerala
• Indian Institute of Information Technology(IIIT) Una, Himachal Pradesh, Una, Himachal Pradesh
• Indian Institute of Information Technology (IIIT) Nagpur, Nagpur, Maharashtra
• Indian Institute of Information Technology (IIIT) Pune, Pune, Maharashtra
• Indian Institute of Information Technology (IIIT) Ranchi, Ranchi, Jharkhand
• Indian Institute of Information Technology (IIIT)Kota, Rajasthan, Kota, Rajasthan
• Indian Institute of Information Technology Bhagalpur, Bhagalpur, Bihar
• Indian Institute of Information Technology Bhopal, Bhopal, Madhya Pradesh
• Indian Institute of Information Technology Design & Manufacturing Kurnool, Andhra Pradesh, Kurnool, Andhra Pradesh
• National Institute of Technology Arunachal Pradesh, Yupia, Arunachal Pradesh
• National Institute of Technology Nagaland, Dimapur, Nagaland
• National Institute of Technology Sikkim, Ravangla, Sikkim
• National Institute of Technology, Manipur, Imphal, Manipur
• National Institute of Technology, Mizoram, Aizawl, Mizoram
• National Institute of Technology, Srinagar, Srinagar, Jammu & Kashmir

To find out more colleges based on your JEE mains performance visit the following college predictor tool:

https://engineering.careers360.com/jee-main-college-predictor

Also to differentiate between CSE and ECE: 

Electronic and Communication Engineering (ECE)It is about electronics and how the different electrical components (Microprocessors, RAM etc) communicate with each other. It has more Physics in it. There is a little programming involved but not much. It focuses on design and implementation of electronic circuits, devices and systems.Computer Science and Engineering (CSE) deals with telling these components what to do and when to do it; by programming them. It has a lot of logic involved and Maths too. Computer engineering is a branch that integrates several fields of electrical engineering  and  computer science to develop computer hardware and software.

I hope this helps.

All the best.