I am also exploring around ... had visited Vibgyor, HMR international School and RCIS.
Fees is high on VIBGYOR and RCIS. If OK with Fees - VIBGYOR standard and environment is good.
HMR - is OK school - Fees also less compare to other two.
You may explore Brigade International School (ICSE) or Chrysalis High, Horamavu (CBSE).