I bought my kit here in US but was wondering if will work in India. Clarification please …
Not likely, although I am not entirely certain. Had a friend try to take a Wink system over, and had nothing but issues.
I don’t know if ST does Geo-Fencing. The Z-Wave should work, I’d think. On the other hand, there is some debate currently… especially after the outages of the last day or so… as to whether ST works even in the U.S. 
I had thought that as long as I have my hub and the devices certified by ST I will be fine but after todays outage i kind of became skeptical as to whether their software/infrastructure is limited to particular geographies.
The following FAQ should be of interest. (This is a clickable link.)
Dear All,
Samsung smartThing will work in India. I bought a smartthing kit from US and using in India.But the problem is its spec says it can work only in 100-110 V system. Still we can connects to 220 V system but it is not recommended. So as a safer side i bought a step down transformer (220/110 V, 750W ) to use smartthing outlets.
For more please watch live demonstration video here : https://youtu.be/csF67HJaPKI
Or better still, buy a kit from the UK.
ZigBee frequencies are identical for each hub version but the Z-Wave frequency is not.
So if you intend buying UK/EU z wave devices as they are 240V then they will not work with a US hub.
You need to check the link as JDRoberts has said as certain frequencies can be illegal.