You can, BUT the mascot itself is not that of Jollibee's property anymore - it'll be outsorced or in short third party. As far as I can remember, when one of the tenants in our building had a Jollibee kids' party, a mascot who's a outsource came and stayed for like 30mins. They said that the client pays directly to Jollibee for the mascot appearance and the resto itself will deduct a certain amount before they pay the talent (mascot).
To add on, just be sure that the venue is good enough to carry Jollibee's reputation. Like they can't be seen in areas that are hmm so-so. Like basket court/ gymnasiums turned to party venues. Clubhouses will do.