section 9 (3) and 9(4)

Dear Mr.Vikram,
U/S 9(3) Govt has specified goods and services for which tax to be paid on RCM basis

Link for List of Goods

https://www.cbec.gov.in/resources/htdocs-cbec/gst/Notification-for-reverse-charge-CGST.pdf

Link for list of Services

https://www.cbec.gov.in/resources/htdocs-cbec/gst/Notification13-CGST.pdf

And sec 9(4) is applicable when goods or services received by Registered Person from Unregistered person .
However, supplies where the aggregate
value of such supplies of goods or services or both received by
a registered person from any or all the unregistered suppliers is
less than five thousand rupees in a day are exempted.

PLS NOTE THAT CBEC SUSPENDED SEC 9(4) TILL 31ST MARCH 2018 AS PER THE RECOMMENDATIONS MADE BY 22ND GST COUNCIL MEETING

thanx sir

welcome Mr.Vikram!!