Paris Saint-Germain broke the world transfer record to acquire the 26-year-old from Barcelona last summer, and the Brazilian scored 28 times in 30 appearances for the French giants before sustaining a broken metatarsal in February.
Earlier this week, it was reported that Neymar had told PSG that he wants to move to the Bernabeu ahead of the 2018-19 campaign.
Ramos has claimed that Neymar "has opened the door" to join the Spanish giants in this summer's transfer window.
"Neymar? He has opened the door for a move here, we will see," Ramos told Cadena Cope.