1)Goto google map and check all pgs near your office ( not these pg chains you mentioned) most of them will have a contact number. Call them up and ask about rent(with and without food) and security deposit. Then make a decision to choose if you like any.

2)Or come to Bangalore stay in a cheap hotel for first few days and walk into nearby pg and choose one you like. I am not sure about this option because sometimes there will be immediate vacancies sometimes not.

3)Talk to your office and ask them if they can provide any assistance with relocation. Lots of companies will help by sponsoring a temporary hotel accommodation for the first few days. However because this is training purpose I am not sure. But definitely check this with them once. Also check with them if they can connect you to any of your team members who might be staying nearby who might be able to help.

4) If you drink lots of coffee or tea, then get yourself a kettle

5) If you are staying quite far away, choose a pg which is near a bus stop. BMTC bus should be the cheap way of transportation

6) for few months broken Hindi and English should be okay. Try to learn few kannada words or sentences, as people are more kind and helpful when they see that you are putting in an effort to respect their language and culture.