If it's client based, how do you plan to expand your software
so that my clients can input data from any where
?
That's contradictory to your client based installation.
At this point I step back. To me "Tally" means a numbers table and I don't think I'll spend the time of a product research to figure out what you might be looking for.
As a side note: Just the phrase "some of ERP systems are already doing it" doesn't make this concept more recommendable...