In the 1st scenario we have to charge CGST and Delhi GST.

While in the 2nd scenario we have to charge CGST and Delhi GST for the services provided in Delhi while we have to charge IGST for all other supplies.

The question is about determination of place of supply and place of receipt of service. Pl read section 12 of IGST Act read with section 2(14) and section 2(15). you will get the answer.

Madanji,

As Mr Singla has correctly pointed out, please refer IGST act relevant sections.

My interpretation is as follows:

in scenario 1 

• Location of Supplier of Service is Delhi,  Sec 2(15)[a] IGST
• Location of Receiver of Service is Mumbai,  Sec 2(14)[b] IGST
• Charge IGST, Place of Supply: Mumbai

In scenario 2

• Location of Supplier of Service is Delhi,  Sec 2(15) [a] IGST
• Location of Receiver of Service is Chennai,  Sec 2(14)[b] & [c] IGST
• Charge IGST, Place of Supply: Chennai

Sec 2 (15): The main Scenario is only from Supply of service. Not to 'To"

Definition of the term “Location of the Supplier of Services” under the Integrated Goods and Services Tax (IGST) Act, 2017

As per Section 2(15) of the Integrated Goods and Services Tax (IGST) Act, 2017, unless the context otherwise requires, the term “location of the supplier of services” means,—

(a) where a supply is made from a place of business for which the registration has been obtained, the location of such place of business;

(b) where a supply is made from a place other than the place of business for which registration has been obtained (a fixed establishment elsewhere), the location of such fixed establishment;

(c) where a supply is made from more than one establishment, whether the place of business or fixed establishment, the location of the establishment most directly concerned with the provision of the supply; and

(d) in absence of such places, the location of the usual place of residence of the supplier.