Possible for RMAN to control backup file permissions automatically..?

Hi

Oracle 10g to 12c

Linux

Backup share mounted via NFS.

At the moment, when I do rman backup, file is created as follows (permissions 640):

total 279G-rw-r----- 1 oracle dba  93G Dec 30 01:24 incr0_20181230_bs37225_bp1_b9tm1fiv_1_1-rw-r----- 1 oracle dba 2.0M Dec 30 01:24 arch_20181230_bs37226_bp1_thr2_seq61625.....

I would like for backups to be created as 644, like this:

total 279G-rw-r--r-- 1 oracle dba  93G Dec 30 01:24 incr0_20181230_bs37225_bp1_b9tm1fiv_1_1-rw-r--r-- 1 oracle dba 2.0M Dec 30 01:24 arch_20181230_bs37226_bp1_thr2_seq61625

Is it possbile to achive this via RMAN, so that backup files are automatically created as 644.