A producer should particularly be knowledgeable about the technical aspects of recording, and how to make a band sound good. You can be as hands off as you want, or you can go as far as the Matrix do and even co-write songs with the band.
Your input should mean something to the band and serve to make them better, push them forward. If they release an album and it flops, you'll be the one to blame, after all, you're the producer. As a producer, you have to be able to make them sound as good as possible, and rock as hard as possible.
Now, as a manager, you have to be able to keep the band in business. If you really want to get hands-on with this, you'll be out there to protect the band's image, book their gigs, make sure they get paid their due, and handling their publicity, if I'm not mistaken. As a manager, you'll have a say in what interviews they participate in, a say in the next direction they'll take, etc. Being a manager is just that, management. You're taking care of this band, concentrating on the business aspects of what they do, like the aforementioned.
This is more of a summary than anything, but it should serve to get you on the right track. Keep it up. Also, if you want to know about the Philippine music business, try talking to musicians who have been in the scene a while and know the ins and outs of things.
I hope that helped.
