Gst number

Query: An Individual is providing IT Services in outside India from India..He is raising Invoices on proprietor basis...He gross receipt is exceeding 20 lakh in next month..He is receiving money in his current account in india. He is Resident Indian. He is filing ITR 4 as 44ADA. Question: (1) Does he need to take GST since his turnover will exceed 20lakh? (2) His services are Export of Service so is it exempt from GST? Yes/No (3) If such service is exempt then is it necessary to take GST Registartion if t/o exceed 20 lakh? (4) if such service is taxable then he need take GST & raise invoice adding GST @ 18% ? Thanks in advance