Because Bitcoins are so limited
The rate of currency inflation is limited (currently just under 11% per year on an annual basis). That is what allows a bitcoin to hold its value.
and 90% of Indian will not have access to real bitcoins
A digital cryptocurrency does require computing hardware and connectivity, but either $40 android devices or dedicated hardware wallets will extend bitcoin to even the poorest regions of the world. Additionally, there will be innovations such as inexpensive scratch-off prepaid cards allowing bitcoin value to be stored and carried by even those with no technology.
so we need a desi version which can be converted to bitcoin
Bitcoin is a proof-of-work based cryptocurrency. It is vulnerable to a 51% attack, however the prerequisite to such an attack is accumulation of tens of millions of dollars of hardware. (though if just ASIC, that amount is still under $10 million today but ASIC hardware is not available in quantity yet, so it will be tens of millions of investment by the time excess ASIC capacity is available).
But alternative proof-of-work based cryptocurrencies (like Litecoin, and especially a new one like you suggested with a desi version) are more vulnerable to a 51% attack. The thickness of the walls of a bank vault need to be the same whether inside is just $1 million or $2 billion. The same issue exists with proof-of-work based cryptocurrencies.
Now Ripple might be something to look at. With Ripple, one might extend an INR loan to another person through Ripple -- a family member perhaps, or even a member of the local community with repayment of the INR loan informally backed by some gold jewelry.
Or Open-Transactions might be the enabler. With open transactions, contracts for any type of asset can be issued and traded. A specific Open Transaction node could even be tailored to a specific community (versus a larger region or nation even).