The Royal Bhutanese Embassy in New Delhi does not issue any visa or entry permit. Bhutanese visas and permits are only issued by the Department of Immigration, Ministry of Home and Cultural Affairs in Bhutan.
Tourists (e-visa) can be applied online here:
https://visit.doi.gov.bt/
This portal contains detailed procedures and documentation required for an e-visa.
Tourists also have the option to apply for e-visas through tour operators, hotels, and tour guides in Bhutan. More information regarding tour operators, hotels, and tour guides is available here:
https://www.tourism.gov.bt/
Business visas must be processed by the business counterpart/inviting organization or company in Bhutan.