If you would like to come to the UK for a short course of studies for six months (or 11 months if you will be studying an English Language course), you may apply for a student visitor visa. In order to be granted a student visitor visa you must satisfy the requirements of paragraph 56K of the Immigration Rules.
If you enter the UK as a student visitor you cannot extend your stay beyond the period of leave granted. This route is appropriate for individuals who may wish to come to the UK in order to undertake short courses such as an English Language course for beginners or a work-related training course.
For individuals wishing to study in the UK for longer, please see guidance on Studying in the UK