When should one start preparing for CLAT

Hy Nikita !!
Normally people start preparing for CLAT at least one year before appering for it because of the tough competition and less number of seats .
You should start preparing for clat one year prior to your exam date  for a smooth sailing.
However , Clat can be cracked in a period of 4 months also but then you have to completely devote yourself to it because the syllabus is so wide that it needs time to retain it in mind. If you are doing something else and can't give a complete year to CLAT , i would suggest you to at least keeo a  note of the current happenings in order to maintain your current affairs. Because this is something which can't  be grabbed in a period of 2 or 3 months . you need to read newspaper daily for it.
I hope this is helpful for you !!
All the best!!