is 200-250 calories burned at the gym good enough for me to loose weight if i go three times per week ?

...

It all depends on how much you are eating, and burning outside the gym.

Total calories in < Total calories out = weight loss.

i am eating roughly 1550 calories a day

i am 15, 6 foot and weigh 223

Have you used the teen calculators to figure out how much you burn in a day?

Well...3,500 calories is 1 lbs.  So at (assume high) 250 calories it would take 4.66 weeks to lose 1 lbs.  That is assuming you do not alter your diet at all.

Alter your diet to consume 250 calories less per day would give you a diet defficit of 1750 calories every week.  Plus your excercise calorie defficit of 750 equals a total weekly defficit of 2500 calories.

Your monthly weight loss would be about 2.85 lbs.

Yes, you would lose weight very slowly.  But it does not take a whole trip to the gym to burn off 250 calories extra.  Simple things like parking far away from your destination, doing laps at the mall and even just standing up and touching your toes will help you burn more calories. 

Lowering your calorie intake is more helpful than excercise alone.  In fact I would say, if you only have stamina to do one thing, make that one thing a commitment to lowering your overall calorie intake.