Which country are you bringing the cat from? Do you have any intention to return with the cat to its country of origin? It is easy to bring a cat to Thailand. However there are some rabies free countries that make it extremely difficult/almost impossible to bring back a cat from Thailand eg. Australia, NZ, UK. For example Australia requires a cat to be rabies vaccinated and spend 6 months in a third country like Singapore, prior to returning to Australia. I would strongly advise to check the requirements for “importing a cat from Thailand” back to your home country, before bringing it into Thailand. Check with the agriculture or primary industries department in your country, or an international pet transport company about the exact requirements for bringing the cat back to your home country from Thailand.
I applied via the soft power route at Sydney consulate. Gave 4 months of bank statements and documents from the school. Approved in 2 weeks, no additional documents needed.