To begin with, the 5-year dual degree program at BITS is significantly more costly than the 5-year iMTech program at IIIT Bangalore, as well as the 4-year BTech program at IIIT Allahabad.

Second, there's no assurance that you'll get CSE at BITS Pilani if you don't have the required CGPA. So, it will be better to consider IIITA or IIITB. 

I have a few friends at IIITB and based on what I heard from them, I will definitely recommend the institute. 

The arguments in favor of IIIT B are as follows.

• No reservations policy as it ensures a good peer group.
• The faculties at the institute are great. 
• The course structure is innovative. There are a variety of courses in the first year, including Calculus using C and Python programming, Algebra Linear, Data Structures and Algorithms: An Overview, Computer Networks with Digital Design. 
• You have the choice of doing a six-month project plus a six-month industry internship in your fifth year or twelve months of study for your master's thesis.
• Good Placements: It has maintained a great placement record over the years. According to the recent placement highlights the highest and average CTC for the institute was 24.88 LPA and 43.31 LPA. 
• Locational Advantage: Bangalore is definitely a much better location than Prayagraj. The climate is great. Air, road, and rail connections are all available. It is in close proximity to MNC offices and top-tier universities (IISc etc). It also offers the conveniences of a big city i.e. malls, restaurants, hospitals, etc.

I know several students in the iMTech program who have chosen IIITB over BITS Pilani CSE and BITS Goa, CSE.