Tourist visas for Myanmar, with a 28 day validity, are available from any Myanmar Embassy or Consulate worldwide.
Visa requirements and embassies
Foreign embassies in Burma
Myanmar embassies.
The borders between India, China and Thailand are somewhat open. You will need to apply to a consulate for permission at least a month or two in advance (They need approval from Yangon) and give a full itinerary of what you plan to do. It is recommended that you keep the application and what you plan to do simple, and if you would like to make any changes then do them in Yangon. You can also apply for permission in Yangon which will take two or three weeks to process.
Visa requirements change regularly and differ from one consulate to the next so phone around.
