I am planning to stay at hotel in Grindelwald
do they provide us with visitor card that I can use it in taking buses or trains. If yes, what area this card will cover.
A list of hotels in Grindelwald can be found here. They will give you a free Visitor's Card, but it does not include trains. The local bus is free, and you'll get a 20% discount on the Pfingstegg cable car. To save on transportation, you'd better look into the rail passes.