How early can you apply?

I'm so sorry as I realise this might have been answered a million times on this sub, but just concerned as I've gotten conflicting info. I have somehow managed to secure an appointment at Edinburgh for France on Jan 31 for a June 22 travel date.

The TLS helpline person told me that I have applied too early and I can only apply 3 months early at a maximum. The official website however states that you can apply 6 months before your intended travel? Would be great to have a confirmation of the correct timeframe to apply. Thanks so much!