To be ortho/para, the side groups always donate electrons, making the benzene more susceptible for electrophilic attack, aka activating groups.
Methyl groups donate their electrons by hyperconjugation (refer to ur ochem txtbook or wiki). Electrons in the C-H can temporarily jump in to the p orbital or benzene.
Electron donating groups will direct the Br ortho and para.
CH3 is a donating group.
Br will be either ortho or para to the CH3 group.
Electron withdrawing groups will donate the Br to the meta position.
COOH is a withdrawing group.
The Br will be in the meta position compared to the COOH group.