libclntsh.so.11.1: cannot open shared object file.

Possibly you want to specify PATH — and also ORACLE_HOME and LD_LIBRARY_PATH — so that cron(1) knows where to find binaries.
Read "5 Crontab environment" here.

Cron does not load the user's profile when running a task and you have to include the profile in your shell script explicitly.

Example documentation

The libs are located in /u01/app/oracle/product/11.2.0/xe/lib (For Oracle XE) or similar.

You should add this path to /etc/ld.so.conf or if this file shows only an include location, as in a separate file in the /etc/ld.so.conf.d directory

I have oracle.conf in /etc/ld.so.conf.d, just one file with the path. Nothing else.

Of course don't forget to run ldconfig as a last step.