var b = {"adultstwin":{"1-4":"q","5-10":"q"},"adultssingle":{"1-2":"q","3-5":"q","6-10":"q"},"adultssinglesup":{"1-2":"q","3-10":"q"}};
function get_key_object(param){
    var c = JSON.parse(b);
    console.log(Object.values(c[param]));
}

get_key_object('adultstwin');