Mujahid force is not regular army. It's the Northern light infantry and classed as paramilitary.
More of a backup force than frontline.
I don't think that's totally correct. Yes, backup force, not frontline, but no, not the NLI.
The NLI were local recruits in Gilgit-Baltistan (in the relevant case, as far as India is concerned, from that part of Baltistan that happens to be in Pakistani hands) who were not organised in formal military formations until after Kargil. In recognition of their deeds (or their sacrifices), they were absorbed into the regular Army as the NLI. According to Nawaz Sharif, who is, of course, a very popular Pakistani politician adored by all young, non-military commentators on defence matters, the entire contingent was wiped out.
That particular member (NOT Safriz) who keeps parroting that the personnel manning the Kargil bunkers who had to be extricated by the Indian Army were mujahids, later substituted by regular army units is a liar; the NLI were incorporated as a paramilitary unit substituting for the numerous paramilitary contingents (including the Gilgit Scouts, who mutinied under Major Brown, massacred the state forces and overran Skardu and besieged Leh in 1947-48) very far back, long before Kargil, and they were the ones who fought to the end in the bunkers. Under the IA indicting fire by the artillery, there was no question of any substitution, on the contrary, the heaviest losses were suffered during their evacuation of the bunkers and their retreat.
Their earlier status was like the Indian Assam Rifles, or the Eastern Frontier Rifles, or some units that dangle between the Ministry of Home Affairs and the Defence Ministry.
The Mujahid Regiment is a regular army unit now, I think; I'm not sure. The point is its composition. It was formed as an initially paramilitary unit, the irregulars who couldn't/didn't get into the AK Regiment; their heritage is the same as the AK Regiment, the Sudans of west Jammu, around 60,000 ex-servicemen with experience of fighting in the British Indian Army in WWII, who banded together long before the Mahsud tribals and those whom we call 'kabiliyas' in folk-lore and popular re-tellings and killed off the very small numbers of state forces in west Jammu, forming themselves into the independent state of Azad Kashmir, with a capital at Muzaffarabad.
They are more or less like our Territorial Army; they form part of the Border Action Teams, along with 'regular' irregulars, the Punjabi terrorist trained by the Pakistan Army and infiltrated into the Vale of Kashmir, and the SSG. They have nothing to do with the Baltis who form the NLI.