Read properly the term and rules. It will surely stated there.
Different bounty have different terms and that includes what's the minimum forum rank they will accept.
If you still have some confusions or need some guidance, you can talk to me privately via PM para na rin di ma spam tong thread.
Please closed your other
bounty related topic concern or pumili ka na lang ng isang thread. Spammy na kasi tingnan pero isa lang pinakaconcern.