Need to compare two strings with one variable

I have two variable as model_name and status. Need to check if model_name is either in model1 or model2 and status is in Failed then have to send mail to users with format 1 else the mail should be sent as the default format.

I tried If [[ $model_name = "model1" ]] -o [[ $model_name = "model2"]] -a [[$status = "Failed" ]] then format1 else Default format fi But this didnt worked and Default format mail is only getting send