Visitor Visa extention for 3.5 week non-academic course

[satj2000]

Hi Guys,
I would like to extend my visitors visa stay as it will ends on 15 November.
I would like to do a 3.5 week non- academic course from 06 January and my passport has a expire on 16 February 2020.
Can I able to get 3 month extension and can I mention the reason that I would like to do therapy course in January which will ends within January month?

Thanks