As a foreign national, you will need a visa to enter Bhutan. The visa is usually obtained upon arrival at the Paro International Airport or at any entry points to Bhutan. It's best to check with your local Bhutanese embassy or tour operator for the latest visa requirements and procedures, as they may change from time to time.
Indian citizens do not require a visa to enter Bhutan. However, they are required to have a valid passport or voter's ID card for identification purposes.
Documents required to enter in Bhutan are:
At Bhutan immigration
In case of not holding the above document, you need to approach to the office of Consulate General of India, India Embassy for getting permission for entry into Bhutan. The following documents are required at the office of Consulate General of India, India Embassy for identification of Indian Citizenship.