Are my bitcoins safe in online wallet
www.blockchain.info for what happens on August 1?
I have my private keys & my account is fully secured.
I really need to know this

Probably not. Your coins were never safe with blockchain.info anyways since they continuously have security and usability issues anyways. If a chain split happens, you won't be able to decide on which chain you want to transact on, blockchain.info will choose that for you.