In India, oil, butter, ghee etc are integral part of our food. Unlike US it is not possible to find a low-calorie variant of a dish at restaurants. Always ask the waiter about the dish you want to tryout. You can ask the waiters in a friendly way to use less oil.
If you cook, always shop for food items at standard shops or super markets and look at the nutrition chart before buying. Do check expiry dates.
There are some good gym-chains like Talwarkars, Gold, Kinase in Bangalore that you can join. Another chain called VLCC (near whitefield) is also there which provide weight lose packages and kind of guarantees you certain kilos of weight-loss.
Let me know if you have any specific question. I too recently shifted to Bangalore, but I am an Indian from up-north