Having to know people studying in these institutes and after doing some research myself, I got to know about some things which might help you get a proper insight, Here are some of the following:
Placements:
| 
			 Categories  | 
			
			 IIIT Jabalpur  | 
			
			 IIIT Allahabad  | 
			
			 IIITM Gwalior  | 
			
			 IIIT Kancheepuram  | 
			
			 IIIT Guwahati  | 
		
| 
			 Highest CTC  | 
			
			 INR 23 LPA  | 
			
			 INR 43 LPA  | 
			
			 INR 42 LPA  | 
			
			 INR 55 LPA  | 
			
			 INR 17 LPA  | 
		
| 
			 Average CTC  | 
			
			 INR 9.9 LPA  | 
			
			 INR 20.8 LPA  | 
			
			 INR 14.6 LPA  | 
			
			 INR 16 LPA  | 
			
			 INR 10.2 LPA  | 
		
| 
			 Top recruiters  | 
			
			 Amazon, Microsoft, IBM, Samsung, etc.  | 
			
			 Adobe, Google, Microsoft, Linkedin, etc.  | 
			
			 Aditya Birla, Finlatics, IIT Patna, Flamingo, etc.  | 
			
			 ShriRam Value Service, TCS, Wipro, UBM, etc.  | 
			
			 TCS, Infosys, Toppr Technologies, Byjus, etc.  | 
		
Based on all the facts regarding rankings, placements, infrastructure, and location, it can be concluded that IIIT Allahabad stands in the first position while IIIT Gwalior is at last.