Could we delete old database and grid version?

We upgraded rac system and I want to ask, could I delete old grid and database version? [oracle@orcl1 app]$ cd 11.2.0.3/ 12.1.0.2/ Middleware/ oraInventory/ 11.2.0.4/ grid/ oracle/ swlib/ I want to ask can I delete manually "rm command line command"11.2.0.3/ and 11.2.0.4 grid files... oracle/product/11.2.0.3 database ... That's my inventory.xml 12.1.0.2.0 2.1.0.6.0 ----------------- EDIT: I started deinstall tool in 11.2.0.3 .. I don'T want to delete grid 12.1.0.2 but I think it can delete 12.1.0.2's grid. right? ######################### CHECK OPERATION START ######################### ## [START] Install check configuration ## Checking for existence of the Oracle home location /u01/app/oracle/product/11.2.0.3/dbhome_1 Oracle Home type selected for deinstall is: Oracle Real Application Cluster Database Oracle Base selected for deinstall is: /u01/app/oracle Checking for existence of central inventory location /u01/app/oraInventory Checking for existence of the Oracle Grid Infrastructure home /u01/app/12.1.0.2/grid The following nodes are part of this cluster: orcl1,orcl2 Checking for sufficient temp space availability on node(s) : 'orcl1,orcl2' ## [END] Install check configuration ## Network Configuration check config START Network de-configuration trace file location: /u01/app/oraInventory/logs/netdc_check2015-11-02_08-53-27-AM.log Network Configuration check config END Database Check Configuration START Database de-configuration trace file location: /u01/app/oraInventory/logs/databasedc_check2015-11-02_08-53-29-AM.log Use comma as separator when specifying list of values as input Specify the list of database names that are configured in this Oracle home []: