What Owner Has To Do, Is Verbal (one Month Notice Period) Is Acceptable From Tenants

If tenants want to leave those room early and he left the room before completing the 11-month rental agreement, tenants have verbally given one month notice period, So what owner has to do, shall we accept those verbal notice period and clear his pending fix deposit or owner need to be written notice period from him (Or if he is not ready to give us written notice period then can we take rent of next month as per existing 11-month rental agreement)