Basically what is your ultimate aim to get from those mantra chanting?
I am a Yog Trainer and I know Healing also.
In my view if you chant some mantraas which has sounds like Aum (OM) and other equivalent sounds which helps to activate your kundalini shakti. And Kundalini Shakti jagrutikaran is helpful.
So it depends on the type of Mantra.
1) If your intention is to focus on Aatma-Tattva, chanting with its meaning will help
2) If you just want to improve the concentration of mind, without meaning of mantra chanting will help
(But it will not give spiritual results.)

Commented by Shreya Jain on Instagram : No it is not relevant because if u don't know the meaning what's the point of chanting . U can do it one time instead of many times but we should know the meaning and do it with our heart ❤️