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

No

While the spelling and the core grammatical function of têm (the third-person plural present indicative of the verb ter) are identical in both dialects, there are significant differences in usage, grammar, and pronunciation:

• Usage (Existential "There are"): In Brazil, it is extremely common and natural to use "tem" or "têm" as a synonym for "há" to express existence (e.g., "Tem gente aqui" instead of "Há gente aqui"). In Portugal, using "ter" in this way is generally regarded as grammatically incorrect or highly informal; the verb "haver" (or "existir") is the standard for expressing existence.
• Grammar (Obligation): When expressing necessity or obligation, Brazilians frequently use the construction "ter que" (e.g., "tenho que ir"). In Portugal, the standard construction is "ter de" (e.g., "tenho de ir").
• Pronunciation: In Brazilian Portuguese, the vowel "e" in "têm" is typically more open and clearly articulated. In Continental Portuguese, vowels are often reduced or "swallowed," meaning the "e" might sound much more closed or nearly silent.

Brazilian Portuguese Usage

1. Eles têm muitos amigos. (They have many friends.)
2. Tem muitos carros na rua. (There are many cars in the street.)
3. As crianças têm brinquedos legais. (The children have cool toys.)
4. Meus irmãos têm um cachorro. (My siblings have a dog.)
5. Eles têm que pegar o ônibus. (They have to catch the bus.)

Continental Portuguese Usage

1. Eles têm muitos amigos. (They have many friends.)
2. Há muitos carros na rua. (There are many cars in the street.)
3. As crianças têm brinquedos fixes. (The children have cool toys.)
4. Os meus irmãos têm um cão. (My siblings have a dog.)
5. Eles têm de apanhar o autocarro. (They have to catch the bus.)