The 2013 Debrett's lists no collaterals for the Earls of Clancarty.
I have come across a burial on findagrave which may pertain to a member of the family, and if so, he may have extant issue:
Frederick Augustus Le Poer Trench
Birth
1863
West Bengal, India
Death
24 Sep 1927 (aged 63–64)
City of Lismore, New South Wales, Australia
Burial
East Lismore General Cemetery
East Lismore, City of Lismore, New South Wales, Australia
https://www.findagrave.com/memorial/217927705/frederick-augustus-le_poer_trenchQuery whether he is the Frederick Augustus said to have been born 1862, son of Henry Luke le Poer Trench (1820-1907). Henry Luke is said to have been "Maj-Gen Bengal Staff Corps", so could well have had a son born in Bengal.
The 1920 Debrett's lists Frederick Augustus and his brothers as unmarried, and does not say where they lived. It does give marriages for his sisters.
Findagrave lists at least one son of Frederick Augustus, who died in 1996. This son was married and may have had issue?