You should apply strictly for a TOURIST VISA and purpose of your visit to India should be travel or tourism (yoga and Ayurveda retreats in Rishikesh, visiting TAJ in Agra etc.). Invitation letter is not required for tourist visa. Please DO NOT mention about joining a yoga course on your visa application form to avoid any complication. You CANNOT get study or yoga visa by registering for our course. Contact details of Indian embassy in your country can be found here. In general, visa expiry date is counted from the day visa is issued. Please verify it with the concerned embassy. Try to apply for your visa at least 2 or 3 weeks before your travel date.
Which kind of visa do I need to apply for?