Tanjiro would definitely take the purple pill. Fighting demons and everything else, he already has super speed because of his breathing abilities. Fighting demons while having to take a dump is the last thing that he needs to do. Trying to swing your sword while holding in a dump isn't something that he was trained to do. Now imagine trying to that on he ice is one of his biggest fears as well. He already has a goofy scar on his face, the last thing that he needs is a shit stain to match while he is playing.

The only other pill that would interest him would be the black pill. Becoming Pt director would allow him to not have to write PT's. This would save him time and give him more free time to attack demons. This would also serve as income for him afford more training. Playing on such a strong team like Baltimore means that he does not make a ton of money. Maybe one day he'll get that big money contract that will help him