Is the word rock the same in Brazilian and European Portuguese?

Yes

The word "rock" is an anglicism used identically in both Brazilian and Continental Portuguese. There are no differences in spelling, grammar, or fundamental meaning. The only differences are found in pronunciation:

• Vowels: In Brazil, the "o" tends to be more open (/rɔk/), whereas in Portugal, the vowel is typically more closed.
• The "r" sound: The articulation of the initial "r" varies between the more retroflex or alveolar Brazilian "r" and the more uvular or tapped Portuguese "r".
• Ending: Brazilian speakers may sometimes add a very slight, almost imperceptible "i" sound at the end of the word due to regional phonetic tendencies, whereas Portuguese speakers tend to end the word more abruptly.

Brazilian Portuguese Examples

1. Eu amo ouvir rock clássico. (I love listening to classic rock.)
2. O show de rock foi incrível. (The rock show was incredible.)
3. Ela toca guitarra de rock. (She plays rock guitar.)
4. Esse festival é só de rock. (This festival is only rock.)
5. Eu gosto de bandas de rock brasileiro. (I like Brazilian rock bands.)

Continental Portuguese Examples

1. Eu adoro ouvir rock clássico. (I adore listening to classic rock.)
2. O concerto de rock foi espetacular. (The rock concert was spectacular.)
3. Ela toca guitarra de rock. (She plays rock guitar.)
4. Este festival é apenas de rock. (This festival is only rock.)
5. Gosto muito de bandas de rock português. (I like Portuguese rock bands very much.)