Open tag of <CONNECTIONSTRINGS>
it will be as below.
<CONNECTIONSTRINGS>
<ADD name="amitpandeyConnectionString" providerName="System.Data.SqlClient" connectionString="Data Source=118.67.248.175\21;Integrated Security=True;User ID=Expresscargo;Password=;Encrypt=True;Application Name=600"></ADD>
</CONNECTIONSTRINGS>