I eat 600 cal per day and hit the gym 6days of the week for1hr30min a day is this right?

I am not a doctor or nutritionist but it is my understanding that anything below 800 cals per day is starvation. You would have to be extremely, EXTREMELY, small for this not to apply to you.

This is an issue because at starvation levels your body goes into survival mode and begins to shut down systems. They still work, but not as well. And your body begins to metabolize parts of your body that you need, such as muscle. Your heart is a muscle.