what does tout droit.prenez la troisieme a droite mean

Answer 1

If you say
"Allez tout droit, prenez la troisième rue à droite",
you are giving directions to someone driving (or walking) to
"Go straight ahead, turn right on the third intersection".

Notice that "tout droit" means straight ahead, and "à droite" (note the "e" at the end) means turn right.

Answer 2

Sorry, there was a problem with encoding. The sentence should have read:
"Allez tout droit, prenez la troisième rue à droite",

Answer 3

In that case, after "Go straight (ahead), take the third STREET to the right.

Sra (aka Mme)