Generally, the GST rate is 5% (2.5% state and 2.5% center) as you noticed.
In November of 2017, the GST council met and decided to make changes
to the original restaurant tax rates. During this meeting, the council
set the GST rate at just 5% for most restaurants, regardless of AC and
I'm not sure about the 9.5% number, but restaurants in high end hotels will charge 18%
If you run a restaurant in a hotel, however, the rules might be
different. For restaurants in hotels with standard room rates of
RS7500 per night or higher, the GST is set at 18%. The 18% rate also
applies to outdoor catering.
The alcohol rate might depend on the state.
If you serve alcohol in your restaurant, your taxes are slightly more
complicated. The GST regime does not include liquor. That means that
when a diner orders a drink, you need to tax that drink at different
rates. Depending on where your restaurant is in India, that could
include VAT and any other applicable state taxes. These taxes must
only be applied to the alcohol part of the bill, while the GST must
only be applied to the food section of the bill.
The above quotes are from https://quickbooks.intuit.com/in/resources/gst-center/gst-restaurant-owners/