According to Official Guinness Records,
The most people playing a clapping game simultaneously is 1,582, achieved by SC Compania de Evenimente ZURLI Srl (Romania), in Domeniul Stirbey, Buftea, Romania, on 16 June 2018.The hand clapping game played is named 'REM POM PI' from Gasca Zurli and is very popular amongst children in Romania.
For a complete list of 2018 records, please visit 2018 Guinness Records in Romania.