Has there ever been a 6–6 in the Liga MX?

Yes, 1 time.

The only time: May 6, 1995, Puebla and Atlante drew (Puebla 6–6 Atlante).

Nearby scores

1. 7–5 2 times
2. 7–6 Never
3. 7–7 Never
4. 6–5 3 times
5. 6–6 1 time
6. 5–5 8 times