I need advise for 300 Sq ft Land located inside city.Can making Herbs garden or Veg Garden will be commercilay be benificial.Should Poly house and Hydroponic be tried in such small area.Market is stone throw distance.Which Varieties should be Tried in Mumbai climate.
300 sq ft is a very small area for farming.
I think your best bet is go for vertical farming using Hydroponics and grow leafy vegetables like dhaniya, methi, palak, lettuce, etc. which can earn you a good income in city like Mumbai.
Mumbai is a good market to try for exotic leafy vegetable.
Alternatively you can also start a unit of Mushroom production.