@husnain,
A 5 kva UPS is enuf to run 1 ton split and fews savers...
will cost you around 50 -55 k.
What i am saying on the other note is that 6 hours now is the prob in khi, you will c what will happen frm may onwards which will easily double as the demand will increase of electricty coz of the heat. Every 1will run ac's hence will go off 10 hours or more.
Every year is worse than the previous one as you may have witnessed.
As far as consumtion is concerned, you can have a genset with gas intalled, and it will not cost you more that 1000 Rs a month to run it on gas, if you have 5 kva petrol/gas generator.
Gas generators are now the most popular products in the market, because the running cost is very cheap. Hence people are queued up to get them.