Between IIIT Allahabad, IIIT Delhi, DTU, NSIT, DAIICT, NIT Calicut, which college should I choose for pursuing CS?

For CS, DTU will be the better choice. Given below are the reasons for choosing DTU over the other institutes. 

The table below can show a brief overview of the institutions:

Advantages - DTU:

• The coding culture at DTU is very developed. Students from all the branches, be it CS or Engineering Physics believes that Coding is the ultimate future of engineering.
• DCECoders is the Codechef made by DTU students. It is the best place to learn coding on campus. 
• IEEE, ASME, CSI, and IET to smaller organizations put effort into the coding competition. From time to time, you will have coding competitions and classes on the campus.
• DTU has over 50 societies that need good coders. Where you can apply your coding knowledge to real-time work.
• Bening situated in the capital of the country, DTU offers good exposure and opportunities. Delhi-NCR is a hub for IT companies, you may be able to get a job in NCR.
• The institute has a rich legacy of over 75 years. It boasts of a strong alumni network. It has a brand value similar to that of old IITs.
• The campus is ragging free and seniors are quite helpful. The 85% Delhi quota at the institute brings affluent crowds of Delhi to the campus.
• The placement process is managed by talented students of the institute. The placement at the institute is great. Even though it is an engineering college the non-technical placement rate of the institute is impressive. 

Even if you realize after a few months of your course that engineering is not for you, you will still get to learn a lot from the campus culture.