I configured as below
mysql> call mysql.rds_show_configuration;
+------------------------+-------+------------------------------------------------------------------------------------------------------+
| name | value | description |
+------------------------+-------+------------------------------------------------------------------------------------------------------+
| binlog retention hours | 168 | binlog retention hours specifies the duration in hours before binary logs are automatically deleted. |
+------------------------+-------+------------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)
But it did not worked.
I got it solved by raising support ticket
https://support.console.aws.amazon.com/support/home?region=us-east-2#/case/?displayId=170313253601514&language=en
I am trying to get it solved for another account , but because i dont have premium supoort, it is taking long time
https://support.console.aws.amazon.com/support/home?region=us-east-2#/case/?displayId=170366567301115&language=en
Request to AWS to resolve this internal issue and provide permanent fix across so that people like me don't have to raise ticket for individual accounts and buy premium support for the same when it is established as internal issue.