Answer would be quite subjective, like, how much have you studied the concepts, how many questions have you done, level of those questions, etc.

Frankly, I found the level of questions was almost similar to that of BITSAT (at least for me). It was just that BITSAT was more of thinking and MU-OET was more of shortcut game (due to very hard time restriction). The questions will be quite straight forward and deal with common problems based on very basic concepts. If you're seriously preparing for big guns like IIT-JEE, then, you might even have seen the questions and memorised their answers. Although, I still recommend to read the questions thoroughly anyway as I myself found some tricky twists at the end of questions.

Other than that, if you mess up first time, you can give it a second go. Heck, even a third go.

Even if you score 145+ out of 200, you have a confirmed CSE seat in MIT Manipal (although you might have to wait for subsequent rounds of counseling).

Best of Luck