Probably. If you're out at the MK bus stop by 6:15, in order to get on that first bus, you should be fine. But, if you just miss that bus, you could be waiting up to 25 mins for the next one. And that would make it tight.
The buses are supposed to be up and running by 6:30, but if you arrive at the bus stop and the bus is just leaving, it could be awhile before the next one comes along. They don't run as frequently as the regular buses do.
You could ask the driver which is quicker over to the CR..walking or monorailing. Walking is faster but this is a 'nice' way to let the driver know you're going to the CR, so you may be offered a CR drop off! But, it's not etched in stone.