can some one advise me i have played alto for a year have now got myself a tenor but dont seem to be able to get some of the notes like the lower ones d c b HELP
This is quite common going to a larger instrument. You must remember to put more mouthpiece in your mouth, use less pressure on the reed & use more air support. Assuming the sax is adjusted correctly (Even new ones from reputable makers come from the factory & store out of adjustment) you should find the low end easier.
What I would say is that to put your mouth on the mouthpiece more. Then lower your jaw a little so that more air comes through the reed. With this happening, the air will get all the way down the Tenor Saxophone and out of the bell.