Which would be the best option energy science from IIT Bombay or power from IIT Bhubaneswar?

The Department of Energy Science and Engineering at IIT Bombay focuses on research and education for the development of sustainable energy systems for the future. The department offers M.Tech in Energy System Engineering with a duration of 2 years. The institute takes admission to the M.Tech Energy System Engineering program based on the performance of the candidate in GATE. For 2019 the GATE cutoff for Energy System Engineering was 750 (General). The first-year course fee for the program is INR 32,000.
According to the placement statistics of 2019, a total of 402 students from M.Tech courses got placements. The average CTC offered was around INR 14.11 LPA.

IIT Bhubaneswar offers MTech in Power System Engineering. The M.Tech program in Power System Engineering focuses on power systems, power electronics, renewable and distributed energy systems, control and optimization, etc. The intake of the students into the program is done through GATE and the expected GATE cutoff in 2020 for Power System Engineering is 495-505 (general category). The 1st year course fee is 2.34 lakhs.

In 2019, 70% of the PG students got placements in many top MNCs with average CTC 11.4 LPA. MNCs like Deloitte, TCS, Capgemini, Goldman Sachs, etc. have participated in the placement drive.

Energy science from IIT Bombay and Power System Engineering from IIT Bhubaneswar are two entirely different branches which makes it difficult to decide which program is best. You should choose according to the branch you are interested in.