Dear student,

If you are participating in josaa counselling, then it's a good thing. Also if you are participating in hbtu counselling, then also it's a good thing.
Both are separate counseling and have no relationship with each other. So, attending the counseling of hbtu will not affect your josaa counselling.
But it will benefit you. Suppose if you do not got any seat in josaa counseling then you will have a chance that you can get hbtu via it's counseling.

Also click of the following link to know more about josaa counseling :-
https://engineering.careers360.com/articles/josaa-counselling