In most cases it will be a requirement of the course that you are competent in the English language. You may need to provide proof of a suitable qualification or be required to sit a short test before you can be offered a place on your chosen course.
The IELTS (International English Language Testing System) run tests that are recognised by most of the institutions on this site. You can arrange to sit the exam by contacting the education department of the British Embassy, High Commission or Consulate in your current country of residence.
Please contact the individual college to discuss the language requirements for the particular course you wish to study.
The British Council runs many schemes to promote cultural understanding of the UK overseas and to encourage learning by overseas students both in the UK and abroad. One of the major areas of their work is the English language: they offer many opportunities for students wishing to study it or to gain a qualification that will be recognised by colleges listed on this site.
Some colleges offer the opportunity for students to improve their English language alongside their studies.
If you are applying to study English, for example on an ESOL (English for Speakers of Other Languages) course, the language requirements will be different. Again, please contact the college to discuss the specific course.