DB6ADMSYS is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "DB6: System administration entry" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_DB6ADMSYS TYPE DB6ADMSYS.
The DB6ADMSYS table consists of various fields, each holding specific information or linking keys about DB6: System administration entry data available in SAP. These include SYSID (Name of SAP System), SAPREL (Release of SAP System), DBREL (DB6: Database Release Level), RFCDEST (Logical Destination (Specified in Function Call))... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .