Did I read correctly, you are putting your lo to bed at 6.30pm & you want him to sleep to 7am... if so that is probably a bit unrealistic.
At 9 months you would expect about 14hours sleep in total over 24hours. Can be +/- about an hour but normally pretty close to the 14 hours. Of which you would expect about 11 hours to be night & then 3 hours in the day either 2x1.5 hours or 1hour +2 hours, although some lo's may do one big long sleep.
I think if 7am is the time you want then you have to put the bedtime later.
around 4/5am is when the last deep cycle of the night starts & if your lo isn't really tired enough to roll into that cycle, they will wake up & never really go back off to sleep, which given that is what your lo is doing proably need to have a later bedtime & also cut back on the day sleep... it could take up to 3 weeks for the morning wakeups to get later, I know it did with us!