Stay after l1b expiry if h1b is filed in april

L1b visa expires in august. Can i stay from august till oct if i file h1b in april? Can you help in this regard? Is there any grace period for l1 b? I saw somewhre there is grace period of 60 days but not sure if that is applicable to l1 b

No, you cannot. In order to continue to stay beyond August you either need to have an approved L-1 I-94, or have at least L-1 extension under pending status.

Grace period is for F-1 and not L-1.