What is the right option for me Cat/gmat considering i have 5 yrs experience

Hi team, I have come here with a lotnof apprehension and self doubt. I aopeared CAT last year for the first time, i prepared for about 6 months and i scored 90%ile. I have 5 years workex currently... all this while I was thinking wherether appearing CAT still an option for me or should I switch to GMAT. If CAT still seems a good option, will I be able to prepare well enough to get tier 1 college in the remaining time. I genuinely need help to come out of these dilemmar. Can anyone please help me with this?