"I'm very happy", Ronaldo said.
Ronaldo and Mourinho are both clients of agent Jorge Mendes.
Also, last month former Atletico Madrid striker Radamel Falcao and Real Madrid defender Fabio Coentrao were accused by the prosecutor's office of not paying all their taxes.
It remains hard to believe Ronaldo will be allowed to leave Real Madrid this summer, but a move to Paris may well be more likely that a return to Manchester if the improbable comes to pass.
A report in Spanish publication AS has suggested Mourinho penned an agreement to become Madrid boss on March 31, 2010.
Now, the admission of the two counts of fraud in 2012 and 2013 will see him pay an additional fine of nearly 780,000 euros.
USA shot down Syrian drone, inches closer to Russian confrontation
Earlier this month , the US shot down another pro-regime drone in the same area after it dropped munitions near coalition forces. The row prompted the Australian government to announce that it would "temporarily" halt its airstrikes in Syria .
Spanish prosecutors have kept up their pressure on football's alleged tax avoiders with Manchester United manager José Mourinho being the latest to be dragged before the courts.
After leaving Madrid, he returned to England for a second spell with Chelsea before joining United, with whom he won the Europa League and the League Cup in the season just finished.
However, Di Maria is unlikely to serve time behind bars as a sentence under two years for non-violent crime can be served as probation, according to the Spanish law.
Mascherano was also convicted of tax fraud last year and was given a suspended one-year sentence.