This is the 9031st most frequent Russian word.
родригесом
"Родригесом" does not have an inherent meaning in Russian; it appears to be a proper noun, possibly a transliteration of the surname "Rodriguez."
In this sentence, 'Родригес' functions as a proper noun, referring to a person's name, and 'которую написал' ('written by') indicates possession or authorship.
Книга, которую написал Родригес, называется 'Моя история'.
The book written by Rodriquez is called 'My Story'.
In this sentence, 'Родригеса' is in the accusative case, showing that this person is the direct object of the verb 'встретил' ('met').
Я встретил Родригеса вчера на концерте.
I met Rodriguez yesterday at the concert.
Here, 'Родригесом' is in the instrumental case, as it is used with the preposition 'с' ('with') to mean 'together with Rodriguez'.