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

&lt;?xml version="1.0" standalone="yes" ?&gt;

&lt;!-- Copyright (c) 1999, 2014, Oracle and/or its affiliates.

All rights reserved. --&gt;

&lt;!-- Do not modify the contents of this file by hand. --&gt;

&lt;INVENTORY&gt;

&lt;VERSION_INFO&gt;

   &lt;SAVED_WITH&gt;12.1.0.2.0&lt;/SAVED_WITH&gt;

   &lt;MINIMUM_VER&gt;2.1.0.6.0&lt;/MINIMUM_VER&gt;

&lt;/VERSION_INFO&gt;

&lt;HOME_LIST&gt;

&lt;HOME NAME="OraDb11203_home1" LOC="/u01/app/oracle/product/11.2.0.3/dbhome_1" TYPE="O" IDX="2"&gt;

   &lt;NODE_LIST&gt;

      &lt;NODE NAME="orcl1"/&gt;

      &lt;NODE NAME="orcl2"/&gt;

   &lt;/NODE_LIST&gt;

&lt;/HOME&gt;

&lt;HOME NAME="OraDb12102_home1" LOC="/u01/app/oracle/product/12.1.0.2/dbhome_1" TYPE="O" IDX="5"&gt;

   &lt;NODE_LIST&gt;

      &lt;NODE NAME="orcl1"/&gt;

      &lt;NODE NAME="orcl2"/&gt;

   &lt;/NODE_LIST&gt;

&lt;/HOME&gt;

&lt;HOME NAME="OraGrid12102" LOC="/u01/app/12.1.0.2/grid" TYPE="O" IDX="4" CRS="true"/&gt;

&lt;HOME NAME="OraGrid11gR3" LOC="/u01/app/11.2.0.3/grid" TYPE="O" IDX="1" REMOVED="T"/&gt;

&lt;HOME NAME="OraGrid11gR204" LOC="/u01/app/11.2.0.4/grid" TYPE="O" IDX="3" REMOVED="T"/&gt;

&lt;/HOME_LIST&gt;

&lt;COMPOSITEHOME_LIST&gt;

&lt;/COMPOSITEHOME_LIST&gt;

&lt;/INVENTORY&gt;




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 []:
Oracle provides a deinstallation tool starting with Oracle 11. 

It's located in $ORACLE_HOME/deinstall/  (in your case the old Homes). It takes care of the inventory and remote hosts in case of a RAC.