Boss it is much much better to go for a 2007-08 LIANA than other options around 7 lacs.
I myself purchased a 2008 LIANA LXi a couple of months ago under the same price banner. If you choose wisely in car selection you can find real good car under 7 lacs here in Karachi.
Preferably go for Petrol only LIANA, you will find many LIANAs here that have no CNG.
Prefer the car having after-market CNG, if you cant find petrol driven only.
Prefer an LXi or Sports model over RXi. LXi has matching door handles, good alloys and additional ABS which is worth. Sports have only 15 inch tyre in upgrade to LXi's 14 inches and some weird body kits (if you like that).
Do check if all the electronics are working correctly, power windows/mirrors, sensors, dashboard lights etc. A nicely maintained one will usually have all such items working.
Do check if the drive is smooth (vibration less) and car does not make any sort of sound over any angle of turning.
Do check the capacity and condition of the CNG cylinder also. A 60L any branded one (Inflex/EKC) is preferred. And kit should be of LR.