निस्संशयः no doubt, कालः inexorable time, तव to you, जीवितान्तकरः ends your life, नूनम् surely, येन since, अवशः an uncontrollable one, बलात् forcibly, सुग्रीवस्य Sugriva's, वशम् under control, अवपन्नः come into the fold.

'No doubt time is inexorable. The time of your death had surely arrived.Now you, whom nobody could control, have come under the sway of Sugriva.