Chill dotard catches close to Bhopal, India (4,2)
I believe the answer is:
cool it
'chill' is the definition.
(I've seen this in another clue)
'dotard catches close to bhopal india' is the wordplay.
'dotard' becomes 'coot' (I am not sure about this - if you are sure you should believe this answer much more).
'catches' indicates putting letters inside.
'close to' suggests the final letters (the close/ending of).
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
The final letter of 'bhopal' is 'l'.
'l'+'i'='li'
'coot' placed around 'li' is 'COOL IT'.
Can you help me to learn more?
(Other definitions for cool it that I've seen before include "Relax" , "In slang, calm down" , "Don't get so excited'" , "Here's what to do before opening champagne" , "Calm down - not so hot." .)