1. Navigate to Communities > Forms > Registration 
  2. Hover over Form Name and select Website Info
  3. Click on Registration Form Options 
  4. On the first page, click Edit by the registration type.
  5. Click the Advanced tab.
  6. Enter in Maximum # of Registrations Available for this Type.
  7. Click Save. 
  8. Return to Website Info and click Publish This Event Now
  9. Repeat for other Registration Types.