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 can't explain this - if you can you should give a lot more credence to this answer).
'catches' is an insertion indicator.
'close to' says to take the final letters (the close of something is the end).
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
The final letter of 'bhopal' is 'l'.
'l'+'i'='li'
'coot' going 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." .)