Juli,
could you please be more precise regarding your problem.
The counter CNRELCONG belongs to OBJTYPE CLSDCCH and is the Number of SDCCHs released due to radio resource congestion. Why do you say that you have TCH Congestion ?
You should check OBJTYPE CELTCHF or CELTCHH, the first one is regarding Cell TCH Full Rate Statistics and the second is regarding Cell TCH Half Rate statistics, both of them have counters for TCH congestion.