gst on Advance payment

actually i entered into contract for providing 5 event services in the month of sept, 2017 and i already recd the whole amount of Rs.10lakh in advance , but out of 5 event , 3 event held in month of feb and invoice also raised for the same of Rs.6lakh in this FY. but for remainig 2 event which will going to be held in the month of may, 2018 and invoice will also be raise i n month of may of remainig amount of Rs.4lakh in next FY.
here i have already paid gst on whole amount but for part of amt invoice will be raise in next financial year in the month May,18. so is it kk ....can i adjust the same agst adv in gstr1 of may,18 on which gst already paid in sept,17

pls..let me know soon