If vaccinated, No pre departure test. If unvaccinated, only negative pre departure test. No arrival test, no quarantine on arrival, evisa available for most countries, no insurance, no hotel bookings.
You have to give them some documents that prove you are only going for tourism, not to work illegally and will be coming back to your own country like job/business papers, tax papers or a heavy bank balance etc which you didn't give .
If you are really interested only in travelling, you have the option of getting a visa on arrival for 15 days which is available for Indian citizens.
David Broadfoot so if a person has entered on a tourist visa, they are eligible to get 60 days family extension if they have wife/children in Thailand ?