saṅgāma (Pali) comes from Sanskrit संग्राम, from Sanskrit ग्राम, from Proto-Indo-Aryan grā́mas, from Proto-Indo-Iranian grā́mas, from Proto-Indo-European h₂ger- — to gather; flock, herd.
Ancestry of “saṅgāma”, step by step
saṅgāma traces back through 3 separate lines of ancestry.