This Sloka is found in the 9th Chapter of the KulArnava Tantram.
PujAkoti-samam stotram stotra-koti-samo japah |
dhyAnam dhyAna-koti-samo layah ||
Stotra is equal to a crore of PujA. A Japa is equal to crore of
Stotra. DhyAna is equal to a crore of Japah and one crore of DhyAna
is equal to Laya.
KulArnava Tantram, Chapter 9, Sloka 36
Here, "Laya" means "dissolution of mind" referring to a Samadhi kind of state which is achieved at the highest stage of Dhyanam. That's why its stated "dhyAna-koti-samo layah".
The verse is talking about some kind of a hierarchy of some spiritual practices like doing a formal worship, chanting mantras, reciting Stotras etc. And the whole Chapter is dedicated to the topic of Kula-Yoga and Kula-Yogis.