How to check if NRIC is valid

Check NRIC

Happen to find this website.

Singapore City Codes

Ang Mo Kio +65 645
Ayer Rajah +65 676
Bedok +65 644
City +65 653
Geylang +65 673
Jurong West, Tampines +65 678
North +65 635
Sembawang +65 675
Tampines +65 677

Source http://www.1areacodescountrycodes.com/international-country-codes-city-calling-code-singapore.htm

Do not seems accurate for me, as I am in Geylang but +65 634