Hi,
Question - 1 : How to find the SAP user last login details
Answer : Please use SUIM transaction to check the last logon details of the user. Please check here SUIM-Overview and uses
Question - 2 : How to find who have added the Tcode in the Role.
Answer : Please use SUIM transaction-->change documents--> roles
Hope this helps.
Regards,
Pradeep