muscle hypertrophy workout

I am 28yr 6'1 and weigh 165 on a good day. I eat 500 cal per meal/ 6 meals a day. Right now am only taking protein after workout. I am unable to get past 165. I workout 5-6 times a week. I’m kind of at a loss of what else to do. Please recommend a workout that would help me put on muscle mass.