Is it required to distinguish whether a particular supply involves supply of goods or services or both

Yes, the CGST Act, 2017 specifies certain provisions separately for supply of goods and supply of services viz., Section 12 and Section 13 thereof provides for ascertaining time of supply of goods and time of supply of services respectively; similarly, separate provisions have been specified for ascertaining place of supply of goods and place of supply of services. Further, the rate of tax applicable to supply of goods and supply of services are different. Accordingly, it is important to distinguish whether a particularBtransaction involves supply of goods or supply of services.

(ICAI FAQ PUBLICATIONS 06-09-2017 SCOPE OF SUPPLY : FAQ NO. 2)