Unfortunately, if you do not travel by car, direct access from Salou to Ronda will not work. You have to go with one transfer.

First you need to get to Malaga by the train Barcelona - Malaga, which on the way makes a stop at the railway station Salou. Trains from Barcelona are sent 3 times a day from the Barcelona-Sants station: at 10:20 and 15:50 - high-speed train, at 8:30 - express train. And already from Malaga you can get to Ronda in 2 hours 45 minutes by bus (ticket price from 5 to 10 EUR). Malaga Bus Station Paseo de los Tilos is located at Paseo Los Tilos, Malaga, 1 km south-west of the city center.