But your php version does not meet Magento precondition.
Please check your php version and update required php version
Hope it will help you.
@Sunil Patel As my magento site is in version 2.2.3 and trying to upgrade to magento 2.3 so, while upgrading I have changed the php version to 7.2 . as magento 2.3 requires php 7.2 .
please have a look and let me know your thoughts.