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.

According, to the latest change 11th class will hold 20% weighatge and 12th class will hold 80% weightage. So, you should prepare accordingly.

You can also solve complete mock test series to analyze your performance level and to know your strength and weakness.

All the Best!!