Both institutes are well known for their excellent education and opportunities offered. So you can choose the branch and college on the basis of your own preferences. However, some points you might want or consider

Campus: NIT Delhi operates from a temporary campus which is located far away from the country and its permanent campus is still under construction. IIT Delhi on the other hand is a fully-fledged established Institute with a fully functioning well facilitated campus.

Placements: Although Textile Engineering has very few core job opportunities, people tend to go for non-core jobs instead to secure a high-paying job at a top company. Meanwhile, NIT Delhi being younger than IIT Delhi has fewer companies visiting campus with CS roles despite being a demanded branch.

If you are actually keen to pursue CSE, go for better Engineering colleges like NITs, DTU, NSIT, and IIIT D. In fact even at IIT Delhi, you can pursue your coding passion alongside your main branch textile and sit for IT placements. The final decision is yours to make and you can consider additional aspects like fees, location, and academics while making your decision.

The choice of college and branch totally depends on your inclination and career prospects. Yet, a few pointers you might consider 

For MBA/ non-core jobs/Startups: IIT Delhi Textile is the best choice if you are looking for any 3 of these options. Its excellent location provides enough exposure to give you access to unimaginable opportunities. Many events hosted by industry experts, CEOs of big companies, and successful entrepreneurs will give a better insight into the startup culture. Moreover, students preparing for competing exams can easily access coaching centers nearby.

Research in Biotechnology: If you are interested in research in general or Biotechnology specifically, then the Biotechnology at KGP is an excellent choice. It is one of the most demanding fields in terms of research and general growth. With a good CGPA, you can find a research internship or you can apply for MS or Ph.D. Even job opportunities are plentiful. 

Campus: IIT Delhi is better because of its small size and location

Lastly, Engineering Physics from IIT Guwahati should be considered only if you are genuinely passionate about Physics and want to pursue a research career in the same. The curriculum comprises high-tech mathematical concepts and is a good option to pursue a career in economics and computer science.

Ranking-wise the preference order of the above-mentioned courses is 

IIT Delhi > IIT Kanpur > IIT Roorkee > IIT BHU

Based on their closing rank, the branches can be arranged in the following order 

Chemical>Metallurgy>Textile 

This was based on general data, but if you have an inclination towards a specific branch, then go for it without much hesitation. Your passion will keep you motivated despite various challenges thrown at you. But in case you have no specific preference, then you can consider the college and branch ranking to make an informed decision.

Apart from CS and Electrical, students from most branches opt for non-core jobs which require much more than their core academics for placements. In that case, you can prefer IIT BHU over IIT Roorkee.

Ultimately, the final decision is yours to make. Choose wisely considering various factors like location, friends, etc,