Gst on hotel tariff

On actual bill amount...........18%

Dear Sir  Iam hotelier. My query is :

1)I have a room with Tariff of 1100/- and i had given discount of 200/- wich net comes to 900/- In which i have to calculate GST now. But as per prescribed slab in GST there is no taxes for below 1000 Rs Tariff, does it mean there will be no taxes on such raised bills. 

2) In other case i have Room with tariff of 900/- and during seasons we had increased the tariff to 1100/-. What will the tax structure here.