Records of NY Militia are in NY, originating in the Counties where they lived. All men aged roughly 16-60 years (varying by time and place) were considered to be in the militia. A large proportion of the militiamen did not see active duty. When you inquired a few months ago several persons did lookups for you on what is available in the basic print resources that were published before 1911.
Detailed records would be where he lived at the time, or in the NY Archives, assuming those mentioning your man survived the fires (last I know of was in 1911). This requires personal in-person research: Albany County Court, Committee of Correspondence records, and any surviving muster rolls were probably sent to the Archives. Other manuscript materials may have been subsequently collected by the New-York Historical Society, New York Public Library, and other collections you can locate by keyword internet search.
For data on whether or not you are related to this person, you'd need to consult the records on where he spent the end of his life, in Canada.
Neither his NY service record nor records relating to his descendants would be found among materials relating to New Jersey during the Revolutionary War.