You start with the type of AC current sensor you want. Most members of this forum from India seem to have no problem finding a Current Transformer as a sensor.
Yes. Current transformers are extensively manufactured and sold. The O P should have no difficulty at all. They should be right alleviate at Bhubaneshwar the capital of Orissa state, and Kolkata the capital of West Bengal state. I assume that the poster might have hailed from one of these regions.
Many thanks to mvs sarma for the pointers he has provided. I have problems finding things in the US let alone India.
The devices you are looking for (Current Transformer) are likely the least expensive and most common for AC current sensing. They look like the attached images.