Dolly, you need to say what variety of tomato that you are growing. Cordons would seem a little stunted to flower at that height but if it is a tumbler or mini bush then it would be OK.

Black Russian is the one at the min I'm asking about

But I have 43 plants and alot of them are Mediterranean that I have grown from seeds from what iv saved from the fruit I bought from the organic shop

Ah, if you've saved seed from toms. you bought then they won't necessarily come true if they were a hybrid.

So does that mean that I will not get any fruit from them ???

No it means the tomatoes may not be the same as the ones you bought in the shop. Given that yours are from an organic shop there is a fair chance they will come true but, in general terms, it is better to buy seed rather than saving from a tomato fruit.

Thank you very much for the advice and help I'm just hoping that iv not done all this work to not get any return but if not it's a learning curve for next time.

Should I leave the flowers on them.

Yes and tap them very gently to ensure the pollen is spread