With room to spare! Im not used to seeing a question like that. Usually its somebody that wants to cram 3 times that amount of fish in a tank half that size.
You could even increase the size of the Barb and/or Tetra schools and add some corys to fill out the bottom. The more Tiger Barbs in the school the less likely they are to harass other fish. Same thing for the Serpaes, but to a smaller degree as they arent as nippy as the Tiger Barbs.
Remember to add that Red Tail Shark last, and if possible get the smallest one you can. The more established the rest of the fish are in the tank the less likely the RTS will bully them later... no promises though.
Here's a useful tool that will help you along. Its just offers up a guideline and sometimes tips.
AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor
Good luck