This is one of the most powerful strotas to keep away evil forced and provide a Kavacha or armour of protection. It is known as the Panchimukhi stotra and you can get more details from the priest of the Panchamukhi Pranadevaru temple in Gandhal, Raichur.
It is generally believed that this strotra keeps a devotee in god physical and mental health.
This is the stotra
“Om namo bhagwathe panchavadanaaya poorva kape mukhe
sakala shatru samharnaya swaaha
(This stotra starts with a prayer to the east facing Hanuman, urging him to free a devotee from all problems created by enemies. The prayer is also for granting happiness.)
Om namo bhagwathe panchavadanaaya dakshina mukhe
Karala vadanaaya Narasimhaiah sakala bhoota preta pramadanaaya swaha
(Here, the prayer is to south facing Narasimha, pleading with him to remove all fear and sins,)
Om namo bhagwathe panchavadanaaya paschima mukhe
Garudaiah sakala visha haranaaya swaha
(The prayer is to Garuda requesting him to free us of blackmagic, fear, poison all ailments,)
Om namo bhagwathe panchavadanaaya uthara mukhe
Aadivarahaaya sakala sampatkaraaya swaha
(Here, we request Varaha for wealth)
Om namo bhagwathe panchavadanaaya oordhwa mukhe
Hayagrivaaya sakala jana vasheekaranaaya swaha
(Hayagriva, who is on top of the idol, is invoked for goodwill.)
Om Anjaneyaya Vidmahe Panchavaktraaya Dheemahi
Tanno Hanumath Prachodayaath.
By the way, the five forms namely Hanuman, Narasimha, Garuda, Varaha, and Hayagriva can also be invoked individually.
If you want to invoke Hanuman, the stotra goes as follws:
“Sri Anjaneyaya vidmahe mahabalaaya
dhimahi tanno Kapi prachodayat.”
For Narasimha, you can chant
“Ajranakhaaya vidmahe tikshanadamshtraya
dhimahi tanno Narasimha prachodayat.
The Garuda Gayatri chant is as follws:
“Tatpurushaaya vidmahe suvarna
pakshaya dhimahi tanno Garuda
For Varaha, you can chant
“Om dhanurdharaya vidmahe
vakradamshyara dhimahi tanno
The Hayagriva Gayatri mantra is
Om vaagishwaraaya vidmahe
Hayagrivaaya dhimahi tanno