I don't know, I seem to remember it being a lot more "indie" based in the old days than it is nowadays, probably because the internet means that people listen to all kinds of things, instead of sticking to one genre because you could only afford to buy a given amount of CDs.

They appear to have abandoned any kind of heavy rock music, but Giles Peterson covers jazz, soul, house and rare groove type stuff, Cerys a lot of world and pre-60s music, Nemone covers what 6 Mix used to instead of doing her normal daytime playlisted show that she used to. That alongside Craig Charles and Don Letts from the early days, and shows like The Freak Zone, Jarvis Cocker (and to some extent Guy Garvey) and Iggy's weekly show (and the various stand ins he has on occasion) playing mostly stuff that's far from any normal definition of "indie music". Even the playlisted daytime DJs like Mary-Ann Hobbs and Lauren Laverne play a lot of the kind of things Phil Jupitus used to get a lot of stick for.

It was probably more indie based as there was much more traditional indie sounding acts in the mid to late 00s, now they arent so common certainly on radio and sounds have moved into different areas more folkish indie or singer songwriters or indie rnb.