What is Mantra, Yantra and Tantra?
Mantra, Yantra and Tantra are esoteric things for Sadhana.
Mantra is the Sound Energy.
Yantra is the Space and Energy — namely body, its chakras and geometric shapes of 2D and 3D as idols or Chakras.
Tantra is the procedure — namely yoga, astrological things like nakshatra, tithi etc namely Time.
Each of these three has varied meaning in every context.
Astrological context is again mixed with many things.
For example : Graha Shanti Puja uses grains, nakshatra at tantra level. Idol of Graha at Yantra level and Graha mantra for the puja.
Space, Energy and Time are ones that has to be connected to Mantra, Yantra and Tantra, astrologically.
Space governs Eye and Ear and its properties namely Seeing and Hearing.
Energy is the body which gives energy to the mantra uttered.
Time is calculated from the horoscope to customize the Tantra.
When these are synced, then the Karma of a person dissolves, good or bad.
Shri Chakra is the one, when customized to a person’s horoscope, brings about this.
So be it. Tathaastu.