| | Maruti Suzuki Wagon-R LXi: Changing / Installing Muffler
No it won't change your exhaust sound. It is just for aesthetic purpose.
For louder sound and more grunt, you need an FFE. Free flow exhaust would need changing of your endcan to a completely different can, which would look great as well as sound more louder and meaner. Cost would be around 5k for cheaper products and upwards of 10k for good branded ones.
For a slight muffled tone, get a turbo whistler thing from ebay.in. It would cost around 700 bucks. It will slightly improve your exhaust note (only at higher RPMs) but wouldn't be visible from the basic outside view.