The affix ṇamul comes after the verbs vartti (the causative of vṛt) and grah 'to seize' when a word denoting 'hand' in the Instrumental -3rd case, is in composition.,
Thus हस्तवर्ते, करवर्ते or पाणिवर्ते वर्तयति = हस्तेन वर्तयति 'he revolves by the hand'. So also, तम् हस्तग्राहम् गृह्णाति 'he takes him by the hand': so पाणिग्राहम्, करग्राहम् &c.
Here also rule 3.4.46 applies and appropriate verbs from the same roots must be employed to govern the gerund.,