It depends on his personality and his reasons of course; but if your DS is one of the many teenagers who hate school, then you may find an FE college suits him better. A lot of kids under-achieve because they are 'activist learners' - i.e. they learn through doing - and school teaching style does not suit them (i.e. sitting still and listening). A tutorial college will be more of the same.
An FE college, on the other hand, will also offer more practical BTEC courses, and will put him through English and Maths GCSEs at the same time if he needs them.
A merit or distinction in a level 3 BTEC is accepted for university entrance... (A friend's son, for example, did the course my son is now doing a few years ago, and graduated last summer with a solid 2:1).
My son under-achieved quite badly at school (and was in trouble a lot) but is now on a BTEC course at our local FE college.
Thanks. My son would be attending year 11 for GCSEs. For several reasons but a fresh start and more focused study than he is doing at his local comp where he is underachieving and not motivated. I hope he won't find being the youngest a problem though. I worry that the majority of students are 16+?