1. Passport: Your passport should be valid for at least six months from the date of entry into Sri Lanka. It should also have at least two blank visa pages for visa endorsement.
2. Visa Application Form: Complete the visa application form accurately and legibly.
3. Passport-sized Photographs: Attach recent passport-sized photographs with a white background. The specific size and quantity may vary, so check the requirements specified by the embassy or consulate.
4. Flight Itinerary: Provide a copy of your confirmed round-trip flight tickets or itinerary showing your entry and exit dates from Sri Lanka.
5. Accommodation Details: Include a copy of your hotel reservation or details of your accommodation arrangements in Sri Lanka, such as an invitation letter from a host or confirmation of a homestay.
6. Financial Proof: Submit evidence of sufficient funds to cover your expenses during your stay in Sri Lanka. This can include bank statements, credit card statements, or traveler’s cheques.
7. Travel Insurance: It is advisable to have travel insurance that covers medical expenses, emergency evacuation, and repatriation. Provide a copy of your insurance policy.
8. Proof of Purpose of Visit: Provide documents that explain the purpose of your visit, such as a detailed travel itinerary, tour booking confirmation, or invitation letter for business or conference purposes.
9. Additional Documents: Depending on your circumstances and the specific requirements of the embassy or consulate, you may need to provide additional documents, such as a cover letter, proof of employment or business, or a return address in your home country.

Tourist visas for Sri Lanka typically allow a stay of 30 days, 60 days, or 90 days, depending on the visa type and your nationality. The duration of stay is usually specified on the visa itself. It is important to adhere to the allowed duration and not overstay your visa to avoid any penalties or immigration issues.

The processing time for a tourist visa to Sri Lanka can vary. It may take anywhere from a few days to a couple of weeks, depending on the embassy or consulate and the volume of visa applications they receive. Some embassies or consulates may offer expedited processing for an additional fee, which can shorten the processing time.