Is GST chargeble on reimbursement invoice

Dear Sir/Madam,
Please help me to sortout some queries on GST

=Is GST applicable on reimbursement invoice raising to client for Travel, Boarding & Lodging etc
= Is any separate registration for ISD (INPUT SERVICE DISTRIBUTOR)
=Is separate registration is compulsory for branches in service provider case
=GST chargeble to SEZ/ export service invoice
=TDS to be deduct under GST
Regards,
Baiju Mishra