Also stand can be bought later, but will be expensive than the wall-mount.
So when choosing you can consider getting the stand for free and later purchasing the wall-mount if required.
The stand is Rs.1000-1200 and you can chose either the stand or the wall mount at the time of installation. When I purchased my C3, I opted for the wall mount and I got it during installation. Within a year (within warranty period), I asked for a stand based installation since I shifted my TV to another bedroom. This time I got the stand free since it was still within warranty period but I paid 900 odd for the installation charges.