hello people.im wondering how many cabin crew does the 777 300 ER take?does it depend on particular airlines?is it more than the 777 200?

This depends on the density of the specific aircraft seat capacity (even at the same airline they may have different density with some configured with J/Y and others configured F/J/Y); length of flight; level of service; and cabin crew contracts.

At a minimum, the US FAA requires one F/A per 50 seats. On some US versions of the 777-200 that would have been a minimum crew of 6(like the DC-10). However, I believe in each carriers Evacuation Certification tests that FAA minimum crew ended up being 8. Most US carriers staff the 777-200 with 8 on domestic routes (unless operated in trans-con markets, with higher service levels) and 11 or 12 internationally, depending on passenger load and service elements on the route.

That said, you should expect the 777-300 to have more cabin crew than the 777-200 as it is a bigger plan, with more emergency exits, and higher seating capacity.