What is the right season and climate to grow broccoli in India?

Broccoli is a cool season crop and head quality is best when heads develop in cool weather, roughly 12 to 24 C. In the north Indian plains it is mainly a rabi or winter crop, with nursery sowing around September to October and transplanting about 4 to 5 weeks later. In hills it can be grown over a longer summer window. If heads mature in heat they become loose, bolt or turn bitter, so time the crop so heading falls in the coolest part of your season. Confirm exact local sowing dates with your KVK because they vary by region and altitude.