Font stylistic sets in illustrator can vary considerably depending on the Illustrator version. However for CS6,

► First select your text with appropriate font

► Then open the OpenType window by going to WINDOW->TYPE->OPENTYPE

► Here you will account numerous options like "Stylistic Alternates" , " Contextual Alternates",

► To view various characters, you might usefully go to WINDOWS>TYPE>GLYPS