Gst related query

12% in case of government contractors. 

Ek or query hai puja mam, ki for example CC road construct krne me Water ka bhi use hota hai or water ek non gst supply hai toh hum inboive me water per gst charge krenge (12%) ya nhi? or jaise sand hai vo 5% me hai toh uss per bhi single rate 12% hi charge krnenge na mtlb ki total taxable value ki single rate hi hogi na? mera ye bahut bada confusion hai thoda isse clear kro...

regards,

What is gst rate for 23099090 and 23099019