Is 6 to 7 hr of sleep is okay ? because i sleep very odd timing 2 am to 8:45 am so is it ok or it affect on my body ? and i exercise 15 dips each mor

Sleep amounts: This varies individually. Some people feel fine on less than 8 hours, some need more. If you are thinking and functioning okay on the amount of sleep you are getting, then continue. It may be your normal.

Not enough: 6-7 hours is borderline and probably not enough at your age. This would be a good nights sleep for someone in their 70's or 80's. You should schedule and plan for at least 8 continuous hours of sleep. Which hours you choose to sleep is your choice but it should be the same 8 hour time period every day .