Hello,
I think John could be the son of Hugh Drummond Junior and Mary McLaren of Auchtubhmore, christened in 1757. Or possibly the son of Hugh Drummond Senior and Janet McGregor, who was also born at Auchtubhmore, but in 1746. My guess is based on location, possible age, (given the age range of their children's christenings), and the names of John and Mary's children. In a large family, it's likely four of the children will be named after the grandparents.
Although the two Hughs lived in the Auchtubh area, and the Senior/Junior is in reference to the other Hugh, I don't think they were closely related. At least, I can't find a record of a link, but it is possible one is the son of the other, and the christening has been lost, or wasn't recorded. I think they were both landowners, (or related to landowners), and their land was seized by the crown after the 1745-1746 rising, because their names appear in the Statistics of Annexed Estates 1755-56, under Easter Auchtubh.
John and Mary are mentioned in John McGregor's Oral Histories, but it talks about their children, and not their parents.
Also, I have Hugh, the husband of Mary Houston, as the son of John and Janet McGregor of Easter Auchtubh, christened 1802. I can't find a record of a Hugh to a John and Mary, but John and Janet matches the census records by age, and by the name of the children, (first born son John, first born daughter Jessie).
John, (and his sons, including Hugh), signed the Acknowledgement of the Chief of Clan Gregor in 1822 as the tenant of Auchleskine.
Janet was the daughter of 1774 Robert and Margaret McLaren, born at Auchtubh in 1777. This is confirmed by census records and the death certificates of her sisters, Mary and Elizabeth, who lived with her son John at Rusgachan. Robert is mentioned in John McGregor's Oral Histories as born around 1741, the sixth generation at Middle Auchtubh, and his father was born around 1701, and died about 1778. Robert was probably the son of the same Hugh Drummond Senior and Janet McGregor I mentioned above, christened 1742.
John was probably the son of Hugh Ban Drummond and Janet McIntyre of Auchtubhmore, christened 1764. Like the two Hughs above, this Hugh is also listed in the Statistics of Annexed Estates for Easter Auchtubh.
In conclusion, it would appear there was a law restricting the people who lived at Auchtubh to those named Hugh Drummond
I hope this helps,
John.