The price between RXI and RXI CNG is about 55k, so if you apply the same to LXI, the price of LXI CNG would be 915k.
Now instead of considering for LXI CNG, i would suggest you go consider RXI CNG, because trust me, liana does fine even without the ABS.
However, at the end its all down to how much budget you have, If you can spare around 11 lac, then go for a corolla, cause that is how much it is gonna cost once you get it registered with alloys, tires etc.
But if you have around 9 lac or less then definitly go for liana RXI.
So at the end its all upto how much you can afford.