Thank you sant, you may be right. However, as Marko wrote, the bi in biserka sounds like the bi in "biturbo". I assume this sounds like bi in bicycle or bite and not bi as in bitumen or bit. I believe I am right with the sa matra as well since sergio is more like serengeti and not sarcasm. I do consent the matra for kaa. These are the arguable differences and So...
Marko, if the bi sounds like bit and the ser sounds like sar then sant is correct and use this... बिसर्का If it sounds like bite and ser (like share replacing the sh with s) then use this...बईसेर्का. That is unless Marko's significant other has a version of the name vishaka, then that changes everything. Good luck Marko and feel free to clarify our questions.
Thanks again Sant...as the saying goes, two heads are better than one.