Here is the analysis of Neech bhang Raj yoga
Neech bhang raj yoga is a powerful rajyoga formed when a debilitated planet gains its power from an exalted planet. When the lord of the sign where the debilitated planet is placed is exalted or if its with an exalted planet it creates neech bhang Raj yoga.

How debilitated planets become strong
A debilitated planet is weak in horoscope so it is very necessary that some other planet supports the weak planet. Neech bhang raj yoga is cancellation of debilitation. But still the debilitated planet affects in personal life but not in professional life.
When a debilitated planet is with an exalted planet or if the lord of the house is exalted then a debilitated planet is no longer weak. Then the debilitated planet becomes very powerful. Support of exalted planet cancels the debility of another planet . Again nothing gets cancelled and everything is addition in astrology.

In this chart, debilitated Mercury is with exalted Venus, so mercury is no longer in debility.
Below are few points that also satisfies cancellation of debility:
A powerful neech bhang raj yoga is formed when a debilitated planet is in upachya houses, 3rd, 6th, 10th and 11th. And the lord or exalted planet of the house occupied by debilitated planet is occupying the kendra house, 1st, 4th, 7th and 10th.
If the lord of the house occupied by debilitated planet is in kendra or trikona from ascendant or chandra lagna.
The exalted planet of the sign of debilitated planet should be in kendra or trikona from the ascendant or moon sign.
If the debilitated planet is aspected by exalted planet.
The debilitated planet is exalted in Navamsa.
If the lord of the exaltation house of debilitated planet is in kendra from the lagna or chandra lagna.
If a debilitated planet is aspected by another debilitated planet or by its own dispositor.
The lord of navamsa occupied by debilitated planet is in kendra or trikon from lagna. Or the lord of lagna is in movable sign.
If the lord of the sign that gets exalted in the sign occupied by the debilitated planet is in trikona from the lord of exaltation sign of the debilitated planet.
If the lord of the debilitation or exaltation house of the debilitated planet are in mutual kendra or trikona from lagna or chandra lagna.
Raja yoga occurs only of the debilitated planet owning a benefic bhava occupies a kendra in a benefic and friendly sign otherwise its debility is removed and it gains the strength.