A few years ago, after reading about Transcendental Meditation (TM), I did a quick search for the mantras. The partial screen shot below is the only site I remember at that time with TM mantras that came up (which at the time of publishing this post is now down with only a page marker to archiving at archive.org).

Naturally, this has changed.
Recently I couldn’t find this screen shot right away so I put off looking for it and did another search. The multiple following sources express varying degrees of sameness and difference of the TM mantras for various reasons (and lack of reasons). What gives? Maybe this is now a promotion to go learn the TM technique, the proper way, from a certified TM teacher?
Above images via https://onhighroads.com/transcendental-meditation-mantras
TRANSCENDENTAL MEDITATION MANTRAS LIST
Mantras Used by TM Teachers Trained in 1961
- Mantra for male students –Ram
- Mantra for female students – Shiram
Mantras Used by TM Teachers Trained in 1969
- Mantra for male students aged 0 to 15 – Ing
- Mantra for male students aged 15 to 30 – Aing
- Mantra for male students aged 30 to 45 – Shiring
- Mantra for male students aged 46+ – Shiam
- Mantra for female students aged 0 to 15 – Im
- Mantra for female students aged 15 to 30 – Aim
- Mantra for female students aged 30 to 45 – Shirim
- Mantra for female students aged 46+ – Shiama
Mantra Used by TM Teachers Trained in 1972
- Mantra for students aged 10 to 11 – Ing
- Mantra for students aged 12 to 13 – Im
- Mantra for students aged 14 to 15 – Inga
- Mantra for students aged 16 to 17 – Ima
- Mantra for students aged 18 to 19 – Aying
- Mantra for students aged 20 to 21 – Ayim
- Mantra for students aged 22 to 23 – Ayinga
- Mantra for students aged 24 to 25 – Ayima
- Mantra for students aged 25+ – Shiring
Mantras Used by TM Teachers Trained in 1976
- Mantra for students aged 3 to 10 – Eng
- Mantra for students aged 10 to 12 – Em
- Mantra for students aged 12 to 14 – Enga
- Mantra for students aged 14 to 16 – Ema
- Mantra for students aged 16 to 18 – Aeng
- Mantra for students aged 18 to 20 – Aem
- Mantra for students aged 20 to 22 – Aenga
- Mantra for students aged 22 to 24 – Aema
- Mantra for students aged 24 to 30 – Shiring
- Mantra for students aged 30 to 35 – Shirim
- Mantra for students aged 35 to 40 – Hiring
- Mantra for students aged 40 to 45 – Hirim
- Mantra for students aged 45 to 50 – Kiring
- Mantra for students aged 50 to 55 – Kirim
- Mantra for students aged 55 to 60 – Shiam
- Mantra for students aged 60+ – Shiama
Mantras Used by TM Teachers Trained in 1987 to Present Day
- Mantra for students aged 0 to 11 – Eng
- Mantra for students aged 12 to 13 – Em
- Mantra for students aged 14 to 15 – Enga
- Mantra for students aged 16 to 17 – Ema
- Mantra for students aged 18 to 19 – Aing
- Mantra for students aged 20 to 21 – Aim
- Mantra for students aged 22 to 23 – Ainga
- Mantra for students aged 24 to 25 – Aima
- Mantra for students aged 26 to 29 – Shiring
- Mantra for students aged 30 to 34 – Shirim
- Mantra for students aged 35 to 39 – Hiring
- Mantra for students aged 40 to 44 – Hirim
- Mantra for students aged 45 to 49 – Kiring
- Mantra for students aged 50 to 54 – Kirim
- Mantra for students aged 55 to 59 – Sham
- Mantra for students aged 60+ – Shama

Please visit http://minet.org/mantras.html the source of the above table for disclaimer. The site also lists Advanced Techniques and TM-Sidhi Techniques.
Easy to remember shortcut to this blog post: https://tinyurl.com/TMmantras