"This emergency number has WhatsApp instant messaging facility and may be accessed only for cals/messages by Indian nationals seeking emergency assistance"
Bhutanese nationals do not require visa for India. Other country nationals who require visa may approach the Indian Embassy.
One can enter India from Bhutan by land route or by regular Druk Air service from Paro airport for Delhi, Kolkata, Guwahati, Bagdogra and Gaya.
Here are some sites from which you can get more information.
Indian nationals intending to visit Bhutan are required to carry any of the two valid 'Travel Documents' (a) Valid Indian Passport having validity of minimum 6 months; and/or (b) Voter Identity Card, issued by the Election Commission of India. No Visa is required to visit Bhutan.
Indians coming to Bhutan by road are required to obtain an 'Entry Permit' on the basis of valid Travel Document from the Immigration Office of Royal Government of Bhutan at Phuentsholing, located on the Indo-Bhutan border opposite Jaigaon, West Bengal.
Similarly, Indians coming by air must posses any one of the above mentioned Travel Document and get the Entry Permit at the Paro International Airport.
The 'entry permit' allows an Indian tourist to visit Thimphu and Paro only. However, any tourist going beyond Thimphu and Paro need to acquire a 'special area permit' from the RGoB Immigration Office at Thimphu on any working days (Monday to Friday)
Climate
During winter (November to March) the minimum temperature drops to minus 10 in the Thimphu valley. Summers (April-June) are very pleasant. One should avoid traveling during the rainy season (July-September)
Places to visit: Thimphu, Paro, Punakha, Wangdiphodrang, Bumthang. Special permits are however required to visit towns other from Thimphu and Paro.
Distance and driving time of important places in Bhutan
Thimphu
Paro
65
2 hrs.
Thimphu
Phuntsholing
176
6hrs.
Phuntsholing
Bagdogra (India)
170
4 hrs.
Thimphu
Wangdi Phodrang
70
3 hrs.
Thimphu
Punakha
77
3 hrs. 15 min.
Punakha
Wangdi Phodrang
13
45 min.
Wangdi Phodrang
Tongsa
129
4 hrs. 30 min.
Tongsa
Bumthang
68
2 hrs. 30 min.
Bumthang
Mongar
198
7 hrs.
Mongar
Lhuntshi
76
3 hrs.
Mongar
Tashigang
90
4 hrs.
Tashigang
Chorten Kora
52
1 hrs. 30 min.
Tashigang
Samdrup Jongkhar
180
6 hrs.
Samdrup Jongkhar
Gauhati(India)
110
3 hrs.
Samdrup Jongkhar
Phuntsholing
380
9hrs.30 min.
Please visit the following sites for more information about Bhutan: