CC Antya 4.226
sei saba granthe vrajera rasa vicārila
Śrīla Rūpa Gosvāmī compiled 100,000 verses, beginning with the book Dāna-keli-kaumudī. In all these scriptures he elaborately explained the transcendental mellows of the activities of Vṛndāvana.
Referring to the words lakṣa-grantha (“100,000 verses”), Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura says that the total number of verses written by Śrīla Rūpa Gosvāmī is 100,000 (eka-lakṣa or lakṣa-grantha). The copyists count both the verses and the prose sections of the Sanskrit works. One should not mistakenly think that Śrīla Rūpa Gosvāmī compiled 100,000 books. He actually wrote sixteen books, as mentioned in the First Wave of the Bhakti-ratnākara (śrī-rūpa-gosvāmī grantha ṣoḍaśa karila).