Hii dear, 

Both the colleges are good at there levels, as both are the part of Delhi University. But, if i go by NAAC rankings for du colleges then IP is more better than gargi, in perusing your philosophy honours courses.

Exposure wise both the college are best, and   faculty wise , gargi is more better.

To clear your confusion,, i m providing you separate overview of both the colleges. 

IP:

 the Placement Cell provides really good placement opportunities with companies such as Holidify, Limeroad and also with various Foundations such as Aashman, Asmat-Asmat (NGO) and with Variety of Technology related areas. 

Infrastructure: Infrastructural facilities at this college are Marvelous. Labs and Departmental rooms have been provide to each department. Whereas, quality of Labs is really good.

college is equipped with all facilities, as far as sports are concerned. Exposure wise, college is equipped with all facilities, as far as sports are concerned. There is a swimming pool, gymnasium, BB court, both wooden and synthetic, squash court, tennis court, shooting range, archery setup, 

Gargi college :

Placements are good here. Every year, good companies like Deloitte and KPMG come  with good packages..The placement committee does a good job in organising the meets. The process of placements is also very well organised.

Infrastructure: The infrastructure of the college is really good

Hope this helped. 

Good luck!