There is no any such kind of official notification for MHT CET 2020 so you can prepare for MHT CET 2020. Here are some preparation tips you can follow given below:

To score good marks in MHT CET refer your text book as syllabus is based on them. Try to solve every question which is given on your text book for your practice.
Try to work on your concepts. Once your concepts are clear you will able to answer all the objective type questions. You can also solve as many as MCQs for your practice.
You can also solve complete mock test series to analyze your performance level and to know your strength and weakness.

Good Luck!