www.sgrticket.trc.co.tz is the official website to buy your bus tickets in Tanzania.
For booking train tickets in Tanzania, you can use the official websites provided by the Tanzania Railways Corporation (TRC). There are various platforms depending on your route:
TRC Booking System: You can also book tickets and check timetables on booking.trc.co.tz
TRC SGR Ticketing: For booking tickets on the Standard Gauge Railway (SGR), visit sgrticket.trc.co.tz
TRC E-Ticketing System: Another platform for online ticketing is eticketing.trc.co.tz