I think it's only for use by Manny Pacquiao for his special events. Here are the bracket sheets. Most of these names you won't recognize but trust me they can play!
It's a small basketball "stadium", but looks like a small gym to me. You mean to play basketball I assume? I'd imagine they may have basketball leagues there for kids all the time.
P.S. It's almost heartbreaking to see how far behind the Philippine economy is lagging other "developing" countries in Southeast Asia. Poverty and corruption is rampant.