Tank size, Water temperature, Fitration / aeration, water parameters i.e. Ammonia, Nitrite, pH, other tank inhabitants etc.
Rapid breathng is usually a sisgn of stress.
Mine sit in one spot all night & day & looks like they're hardly breathing at all ......so i know they're happy!
Goonch like cool water , 68- 71 & as much current as you can give them plus tons of Aeration.
Cold water holds more O2. That's why they like the cold water (68 to 74 temps). O2 exchange happens at the waters surface. You need a lot of water flow and that water flow should be directed at the water surface creating a lot of movment. Your fish breathing hard is most likely a water issue. Your water may be to warm, dirty, or stagnent for the goonch.
I'm guessing your tank temp is to high...like it was mentioned colder water is the norm for bagarius catfish unless slowly acclimated to warmer tropical temps over several weeks/months.