When hillary clinton won the plurality of votes in california during the 2016 election, and california had 53 representatives in the house of representatives, how many electoral votes from california did she win?

She won 55 electoral votes

Electoral votes are based on the number of representatives which is based on the popular vote and decided by the census which is conducted every 10 years. You add two more to that number which comes from the senate people since there's 2 people for every state in the senate, and for California it brings it to 55 electoral votes overall.