Step 1: Understand the question.
We need where the India Energy Transition Summit 2026 was held.
Step 2: Identify it.
The summit was held in New Delhi.
Step 3: Why New Delhi.
Big national policy summits with ministers and global investors are usually held in the capital for easy coordination.
Step 4: Rule out others.
The Rann of Kutch has renewable plants, and Ranthambore and Dhanushkodi are tourist sites, but high-level summits happen in New Delhi.
Step 5: Conclude.
The summit was held in New Delhi.
Answer: New Delhi