Om Vang Me Manasi Pratisthita – in sanskrit with meaning – mantra from Upanishad

वाङ् मे मनसि प्रतिष्ठिता
मनो मे वाचि प्रतिष्ठितम्
आविराविर्म एधि
वेदस्य आणीस्थः
श्रुतं मे मा प्रहासीः
अनेनाधीतेनाहोरात्रान्सन्दधामि
Om Vaanga Me Manasi Pratisstthitaa |
Mano Me Vaaci Pratisstthitam |
Aavira-Avir-Ma Edhi |
Vedasya Ma Aanniisthah |
Shrutam Me Maa Prahaasiih
Anena-Adhiitena-Ahoraatraan-San-Dadhaami |

Meaning:
1: Om, Let My Speech be Established in My Mind,
2: Let My Mind be Established in My Speech,
3: Let the Knowledge of the Self-Manifest Atman Grow in Me,
4: Let My Mind and Speech be the Support to Experience the Knowledge of the Vedas,
5: Let what is Heard by Me (from the Vedas) be Not a mere Appearance
6: … but what is Gained by Studying Day and Night be Retained.

ऋतं वदिष्यामि
सत्यं वदिष्यामि
तन्मामवतु
तद्वक्तारमवतु
अवतु माम्
अवतु वक्तारामवतु वक्तारम्
शान्तिः शान्तिः शान्तिः

Rtam Vadissyaami |
Satyam Vadissyaami |
Tan[d]-Maam-Avatu |
Tad-Vaktaaram-Avatu |
Avatu Maam |
Avatu Vaktaaram ||
Om Shaantih Shaantih Shaantih ||

Meaning:
7: I Speak about the Divine Truth,
8: I Speak about the Absolute Truth,
9: May That Protect Me,
10: May That Protect the Preceptor,
11: May that Protect Me,
12: May that Protect the Preceptor, May that Protect the Preceptor,
13: Om Peace, Peace, Peace.