Interest demand u/s 234B and 234 C

I filled it return for A.Y 2017-18 in Wichita I claimed relief u/s 89 my return was processed by it cpc and relief allowed but demand interest u/s 234B and 234C on relief amount so I confused I want to know exact rule that which amount is eligible for interest computation u/s 234B and 234C gross tax liability or net tax liability after tax relief u/s 89 .my whole tax paid through TDS