Freelander V6 Gearbox Issue

Hi Folks, Just signed up. I am a wheelchair user and very dependant on my vehicle for my race wheelchair and general getting about.

I have a Sept 2002 V6 Auto Freelander ES model. Which had a dry gearbox and is clunking into gearsboth at standstill and whilst driving.
I realise worst case scenario is a new box but please someone tell me this is a possible fix - There is a Tech Light on in the dashboard too.

Many thanks in advance

Light a match and burn the fooker