Hii..

The MU-OET is an exam which can be put between JEE Mains and state level exams in terms of difficulty. The difficulty of questions is less than Mains but harder than state entrance exams. The exam demands a lot of speed and you have to be on your toes as you get only 45 seconds for each question. No other entrance exam requires so much speed. Also another stand out feature that this exam has is that the questions from different subjects are jumbled. Example: the first question can be from Maths, next one from Chemistry and the next from English. So you can't settle down with a subject of your choice and searching for questions from a specific subject would be a total waste of time. You should also remember that English and logical reasoning will be asked in the exam, so it'll be beneficial to brush up those subjects a little bit. The exam also doesn't have negative marks, which gives you the liberty of guessing the answers.  
Last year the exam had 200 questions to be answered in a span of 2 and a half hours. The year before that, had 240 questions to be answered in 3 hours. If you are able to get around 70% of the marks then it guarantees you a good branch in MIT.
And if you are preparing for the IIT JEE (or JEE advanced) then this exam should be a stroll in the park. 

All the Best!!