Assuming you are asking for BITSAT 2017 preparation so you can consider below points -

Step 1: Check previous years question papers - BITSAT isn't remotely as tough to crack as the JEE is so better to check the question papers first.

Step 2: Download the syllabus and study it carefully if you feel so - This step is very much complementary to 1st step. However, to crack BITSAT in 1 month, you need to know the syllabus well.

Step 3: Take a number of online tests - The importance of taking tests before the actual exam needs no special emphasis. As already pointed out, this is a competitive exam and not a 2 year long course in college.

Step 4: Allot 1 hour everyday to reading a good newspaper -This might seem weird to those who are still not clear about the format of the exam. Here, out of 150 questions, 25 are reserved for Logical Reasoning and English Proficiency.

Step 5: For PCM, earmark specific areas to concentrate on - BITSAT wont test your intelligence the way JEE does by framing slightly tricky questions. You can crack BITSAT in 1 month, armed just with the crystal clear concepts from NCERT.

Hope this helps!!!