The MFA Spokesperson said:

The Singapore Government is saddened by the crash of Lion Air flight JT-610 on 29 October 2018. We are monitoring the situation closely. Singapore has offered to assist the Indonesian Government in any way if Indonesia requires it.

MFA is in contact with the Indonesian authorities and so far there has been no reports of any Singaporeans on board flight JT-610.

Source:Ministry of Foreign Affairs of Singapore