Gst rate query on under construction property

This discussion concerns a query about the Goods and Services Tax (GST) rates applied by a builder on an under-construction flat. The builder is charging 8% GST on the flat cost and vehicle parking (HSN 9954), and 18% GST on advance maintenance charges and security deposits under the same HSN code. The user is seeking clarification on whether these rates are correct, as 8% GST is not a standard rate.