You can take your test in either a Manual or Automatic transmission vehicle. If you pass using an Automatic then you are entitled to tow using only an Automatic transmission. If you pass using a manual transmission vehicle you are entitled to tow either manual or automatic vehicles.
Your vehicle must be legal and roadworthy and have no warning lights showing, e.g the engine management system warning light.
It must not be subject to a manufacturers safety recall, you may be asked for evidence that your vehicle has had the work carried out, is exempt from the recall or that after being checked no work was necessary.