Tekken as an Esport is not popular for betting all around the year. At Least not outside of Asian regions. You can still bet but you wouldn’t know whom to bet on as you wouldn’t know the players.
It is slightly better to wait for major tournaments where world-renowned players face off each other like at the EVO Championship Series. These players play all around the year and you can track how they play, what’s their skill level, strengths, weaknesses, and form, as they usually stream their gameplay or fight in smaller tournaments all year round. Knowing the players will help you make better decisions.