Yes you can.
And you can do it within 4 years if you plan carefully. Let’s say you want to repeat your 2–2. Plan for PS2 in 4–1 and try to finish all the courses (other than what you want to repeat) till 3–2. Leave one course so that you are allowed to take semester (bits would not allow you to take semester if you have finished eligibility sheet requirement). and then, take all the 2–2 courses again. Similarly, if you want to repeat 2–1 courses, opt for PS 2 in 4–2.
If you have problem of NC then you might have to take 1 extra semester. I’m not sure about this but apparently BITS allows only 2 extra semesters. So if you are not able to finish your degree in 2 extra semesters then you will have to leave BITS without degree.
Personal advice: focus on upcoming courses, try to get straight As then your CGPA would be decent enough and you would not need to worry about placements. Instead of repeating courses, take new courses and learn and enjoy your college life.
PS: I have been through similar stage. My 2–1 SGPA was 4.8 and CGPA was 5.8 and I wanted to repeat entire semester. Later I decided not to and took new courses. Now my CGPA is 7.18 and hopefully it will be 7.56 next semester (due to 20 units PS2).