If condition with multiple strings to verify

My script requires to validate a variable against a set of strings. below is my if condition. Anything wrong with it? It shows syntax error.

SourceCluster=$1

DestCluster=$2


if [[ "$SourceCluster"  =~ ^(PreANADC1|PreANADC2|ProdANADC1|ProdANADC2|PreOPRDC1|PreOPRDC2|ProdOPRDC1|ProdOPRDC2)$  || "$DestCluster" =~ ^(PreANADC1|PreANADC2|ProdANADC1|ProdANADC2|PreOPRDC1|PreOPRDC2|ProdOPRDC1|ProdOPRDC2)$]]

then

        echo "SourceCluster or DestCluster options are invalid"

        printf " Values accepted for source and destination clusters are : \n PreANADC1 \t PreANADC2 \t ProdANADC1 \t ProdANADC2 \t PreOPRDC1 \t PreOPRDC2 \t ProdOPRDC1 \t ProdOPRDC2 \n"

else

echo "SourceCluster or DestCluster options are valid"

fi