Regarding turnover

Yes he can file 9c

Turnover for eligibility of filing of reconciliation statement: It may be noted that the
aggregate turnover i.e. the turnover of all the registrations having the same Permanent
Account Number is to be used for determining the requirement of filing of reconciliation
statement. Therefore, if there are two registrations in two different States on the same PAN,
say State A (with turnover of Rs. 1.2 Crore) and State B (with turnover of Rs. 1 Crore) they
are both required to file reconciliation statements individually for their registrations since
their aggregate turnover is greater than Rs. 2 Crore. The aggregate turnover for this
purpose shall be reckoned for the period July, 2017 to March, 2018 . this is press releases on dated 03.07.2019 by cbic

Fir July 2017 to March 2018 turnover is below 2 crores, then there is not requirement of GSTR-9C

It's up to you to go with 9C but it's not mandatory as your turnover is less than 2cr between July to March.