Gst applicability

Hi Sir/Madam

I  have a doubt about GST tax, can you please advise anyone on this.

1. End Customer is placing the PO to Partner

2. Partner is placing the PO to Distributor

3. Distributor is placing the PO on XYZ/ABC company, 

now the query is 

1. billing & sipping to Distributor (Maharastra) from XYZ company (Karnataka) what is the tax applicable, actually End Customer is in Tamilnadu

2.billing to Distributor (Maharastra) and shipping to End customer (Tamilnadu) from XYZ company (Karnataka) what is the tax applicable.

3.billing to Distributor (Maharastra) and shipping to End customer (Tamilnadu) from ABC company (Maharashtra) what is the tax applicable.

please help me on this. 

Regards

Murali