I see a few Ryan's as follows in the Tithe listing for St. Mary's Clonmel - no Michael. The links show images of the Tithe registers, the entries include the reference number shown, the left/right indicates which side of the page to check, the listings include the name and the street,district or townland. I've added my notes in square brackets - e.g. for more usual spelling for townlands etc:
Jno. [John] Ryan, Irishtown southside (ref. 721)
Jas. (James] Ryan, [..unclear.], (ref. 659/left)
Jno. Ryan [..unclear..] (ref. 631/left)
Jas. Ryan, Kilshulan Street[?], (ref 337/right)
Ed. Ryan, Kilshulan Street[?], (ref. 304/left)
Bryan Ryan, Lynaierla [Lyranearla ], (ref. 230/left)
Timy. [Timothy] Ryan, Poulnaginogue [Poulnagunoge] , (ref. 226/left)
Owen Ryan, Poulnaginogue [Poulnagunoge], (Ref. 227/left)
Jer. & Roger Ryan, Knockalisheen, (ref. 175/left)
Thos. [Thomas] Ryan, Knockalisheen, (ref. 175/left)
Danl. [Danie] Ryan, Nucklucas [Knocklucas], (ref. 144/right)
Jas. Ryan, Nucklucas [Knocklucas], (ref. 148/right)
Hacket, Ryan, Donahy, Beats, Power etc , Nucklucas [Knocklucas], (ref. 149/right)
Jno. Ryan, Spa, (ref. 162/right)
Jas. Ryan, West Scrouthea, (ref. 79/right)
Most of the entries relate to locations outside the town, just the first 5 of the above are in the town.
no Ryans mentioned as lessors at Burgagery-Lands East or West
I dont see a date for these particular entries, but probably around the mid to late 1820s or early 1830s, so most likely a generation or so earlier than the Michael Ryans you mentioned (Griffith's Valuation is dated 1850 for St. Mary's). There are some additional Tithe entries in a seperate section, all of these seem to relate to areas outside the town
.p.s. Griffith's actually gives more specific locations for your Michael Ryans :
Michael Ryan, Thomas Street, Burgagery-Lands West (*), house office & yard (* this portion noted as outside the municipal boundary)
Michael Ryan, Healy's Lane, Burgagery-Lands West (*), house office & yard
Michael Ryan, Irishtown, Burgagery-Lands West (within the municipal boundary), house
Michael Ryan, Shelmadan's Lane, Burgagery-Lands West (within the municipal boundary), house
based on the properties held, it doesn't appear that any of these Michael Ryans were farmers, so if they were around for the 1829s/1830s it's unlikely they would be included in the Tithe records.