About applicability of IGST or CGST And SGST

you make Export Invoice & charge IGST

Fall Under Export Services , IGST to be charge , If Lut is filed then no need charge IGST

Yes... It's under export of Service...
IGST will be chargeable. Also You can file LUT without charge IGST.

Sir what is the Meaning of LUT

Letter Of Undertaking, The Govt. has given option to Taxpayer that if LUT is filed then No need charge IGST on export.

Steps to file LUT on line on Portal

Step 1: Login to GST Portal
Step 2: Go to ‘SERVICES’ Tab > ‘User Services’ > Select ‘Furnish Letter of Undertaking(LUT)
Step 3: Select the financial year for which Letter of Undertaking is applied for from the ‘LUT Applied for Financial Year’ drop-down list. Eg: 2017-18