These are very different choices and you should first make up your mind on the choice of stream.

Here is the relevant information on each stream from the different institutions:

• Economics at IIT Kharagpur: It offers a BS (Bachelor of Science) in Economics. It is a 4 year full-time on-campus program. The course fee for the first year is INR 2.24 Lakhs, while for the next three years, it is INR 2.17 Lakhs each year. During IIT Kharagpur placements 2023, the Highest Salary reached INR 2.68 CPA.

• B.Tech Electrical at IIT Bhubaneswar: It is a 4 year full-time on-campus degree offered at IIT Bhubaneswar. The course fee for Electrical at IIT Bhubaneswar is INR 2.74 Lakhs in the first year and INR 2.68 Lakhs each for the next three years. In the 2023 placements, up till the present date, the highest package offered to the Electrical Branch is INR 44.62 LPA and the average package offered is INR 19.05 LPA. The placement percentage for the electrical branch stands at 85.25%.

• IIT Mandi Electrical: The four-year electrical at IIT Mandi has a course fee of INR 2.85 Lakhs in the first year and INR 2.63 Lakhs each in the remaining three years. Hostel fee is around INR 7500. In the year 2022, 47 out of the 48 eligible students from the Electrical branch were placed. The total number of placement offers received by the Electrical branch was 62. In the year 2023, the highest salary offered at IIT Mandi placements was INR 60 LPA and the average salary was INR 25.23 LPA.

• IIT Guwahati Civil & IIT BHU Civil: Civil Engineering at IIT Guwahati is a 4 year full-time on-campus program. The course fee for the same is INR 2.57 Lakhs in the first year and INR 2.12 Lakhs in the next three years. During the 2023 placements at IIT Guwahati, the highest domestic salary reached INR 1.1 CPA, while the highest international salary was INR 2.4 CPA. The top recruiters were American Express, Qualcomm, JP Morgan, and C-DoT, among others.

IIT BHU Civil Engineering is a 4-year full-time on-campus degree. The course fee for the first year is INR 2.28 Lakhs, while for the next three years, it is INR 2.13 Lakhs each. During the 2023 placements, the placement percentage for the Civil Engineering branch was 76.98%. The median package was INR 15.75 LPA and the Average Package was INR 19.09 LPA.

All the above institutions carry the prestigious IIT tag but to compare all of them that too using different courses is quite difficult. You must first choose the course that you wish to pursue and then decide which of these institutions best fulfills all your goals. 

You can use the above statistics for course fees and placements to get a rough idea of each.