Hi Imitiyaz
The weldability of stainless steel depends on which SS material you are dealing with. The carbon and alloy content has an influence on weldability. Typically your "L" grade austenitic stainless steels, such as Type 316L SS will have improved weldability compared to just Type 316 SS due to its lower C content of 0.03% compared to 0.08% in the latter SS. The most useful method of assessing the welding charcteristics of SS is by means of the Scheaffler Diagram. The diagram accounts for the influence of alloys (nickel and chromium) on the weldability of the material. It shows the effects of dilution and the amount of ferrite (least favourable phase) that is to be expected.
I would also suggest that you contact one of your major stainless steel producers/suppliers for more information on the weldability of a particular grade of SS you're inteested in.
Good Luck
VN