I'd like to reformulate your question: "What may drive the indians to integrate additional munitions in FGFA"?
Of course, they can demand some additional A2G weapons, that domestic version of PAK FA doesn't need just because we have much more suitable types and platforms, which indians haven't and won't have in foreseeable future: Su-34, Tu-22M3, Tu-95MS, Tu-160, PAK DA, SSN's with cruise missiles, etc. But anyway, i'm pretty sure that it's not a such good idea to integrate such a monster, like Brahmos or any other heavy cruise missile, with a stealth tactical fighter, like FGFA. It'll be much better to leave this job to Su-30's and concentrate FGFA on the air-superiority and SEAD missions.