Alright, I went through the DGISPR conference.
Some takeaways from the conference and what I understand -
From Kuntal Biswas's analysis, seems like it is indeed BrahMos CM.
It was initially headed for Mahajan firing range, south of Suratgarh, which might imply it was a routine test-firing.
The missile took a sharp, abrupt turn after Suratgarh and entered Pakistani territory, and thereafter crashed/hit after some 124 km (potential navigation failure ?).
The missile was unarmed (without warhead), which further shows it was unlikely a hostile action.
The drop tank shown, is probably dropped in haste by PAF jets scrambling to intercept it.
Conclusion:- It was a test trial, navigation failed and it veered inside Pakistan and crashed. Basically, we fucked up.