I've just purchased RTX TJ 200 would like to know if I can repair manual or where I could purchase spares in the UK please. TIA.

If that's the chrome framed, Russian engined, RTX from thirty-odd years ago then I think you will be out of luck.   Not many were sold and I doubt if spares supply was great even then.  

That bike was so bad it was even worse than the long defunct Aspes Yak - I kid you not.

The fuel cap alone weighed the same as a manhole cover! You bought yourself a lovely boat anchor there, mate ⚓️. Wait till the price of scrap iron rises again and you might break even!.....and I'll bet my plums that, back then, TMX said it was an ideal clubman/starter bike and soooo much better than last year's model ?

If I remember rightly the rear mudguard was a fibreglass affair, not too good