Well I had a PPL (FAA) last year and they didn't let me sit for the Oct attempt. When I emailed the CEO VP Massey, he said I need a CPL before I can sit for the CPL conversion exams.
This is what it exactly said, "(4) You are holding PPL from foreign country , therefore not eligible to writeCPL papers. You are eligible to appear fpr the conversioin to Indian PPL only "
And of course you need some flying hours before you can apply for a computer number.