Rs. 10K for a PnS teleconverter! Most SLR lens converters cost that much!

Honestly, I don't think a screw-on filter like converter would be worth that kind of money. Especially, if you consider that there will considerable loss in the quality of the images produce, with increased chromatic aberration, loss in resolution, etc.

If your budget permits, buy a DSLR with decent lenses, otherwise, save up until you can that, because that's the only way you can reach long focal lengths without losing quality.

Regards,
Aditya