Is the condo's HOA tax deductible if I use the condo as my primary residence but also rent one room to a tenant?
Yes, but only the percent that represents the one room you're renting.
When you set up your condo as a rental asset, you had to come up with a cost basis dollar amount for the one room. Use that same percent of one room rental versus your total condo square footage to see how much you can deduct.