Well 6:30 is about average for lightweight collegiate males in the US (some faster some slower depending on the conference and level of program). Most of them are doing lots and lots of volume (see 2x workouts a day of anywhere from 15-20k a go for their steady state pieces, and shorter work for their AT/AN work.
Now, I have a bit of different view points then many rowing coaches in that I believe raw strength can truly make up for a lack of volume (though truly volume is needed a good bit).
So depending on the amount of time you have to allocate to rowing and to lifting I could make you a program or point you in the right direction (those I train/coach probably wouldn’t appreciate it if I made you out a detailed program for free).
That being said first and foremost you need to do a 2k, with the digital setting at 130-140 depending on your strength. Read through this thread to see how to check the digital rating if you’re unsure as I’ve outlined it previously here.
Once you’ve done that then I’ll have more information as to what you should be doing in terms of heart rates and training ranges.
Regardless of what you pull chances are you’ll be needing to put in a solid 5-6 sessions on the erg/water a week and 3 in the gym. This would be minimum for the goal you have outlined.
Other information that’d be helpful (though not necessary):
Age, weight, height, approx 1RM in squat, deadlift, clean, 6k time, 10k time, 60 minute distance (in meters).
More info that you’ll likely have less access to:
VO2 Max on the erg, Max Watt output at quarter, half, and 3/4 slide. Max wattage in 10 strokes. Wattage for 30 seconds. Lactic Acid Threshold heart-rate (where your body switches from aerobic to anaerobic) on the erg.
One thing to note that VO2 max and other various lactic acid testings vary depending how you test. A test on the treadmill will vary from a test on the erg due to the different biomechanics and difference in how well your body is trained at the specified movement.