Vedic Hindu cosmology defines various different lokas(worlds) within countless universes where Atma takes birth as different creatures depending on previous Karma. I want to know about Ramakrishna's views or teachings about the same.
In Chapter 47 of The Gospel of Sri Ramakrishna it reads:
SHYAM: "You can learn from Theosophy where the soul goes after death —whether to the lunar sphere or the stellar sphere or some other region."
MASTER: "That may be. But let me tell you my own attitude. Once a man asked Hanuman, 'What day of the lunar fortnight is it?' Hanuman replied: 'I know nothing about the day of the week, the day of the lunar fortnight, the position of the stars in the sky, or any such things. On Rama alone I meditate.' That is my attitude too."
Sri Ramakrishna did not encourage speculating about these things at the beginning. He wanted people to realize God instead. I do not recall anyone asking him about Lokas in the Gospel but if they did he would surely not answer the question.
SHYAM: "Sir, is there such a thing as reincarnation? Shall we be born again?"
MASTER: "Ask God about it. Pray to Him sincerely. He-will tell you everything. Speak to Jadu Mallick, and he himself will tell you how many houses he has, and how many government bonds. It is not right to try to know these things at the beginning. First of all realize God; then He Himself will let you know whatever you desire."
The Gospel of Sri Ramakrishna, Chapter 48, In the Company of devotees at Syampukur
Though Sri Ramakrishna did not say anything about Lokas, there is one incident in his direct disciple, Swami Subodhanada's life, in which there is a mention of Ramakrishna Loka - the spiritual realm of Sri Ramakrishna.
Swami Sambuddhananda was a disciple of Holy Mother Sri Sarada Devi. At the invitation of the Vedanta Society of Hawaii, he visited Honolulu twice nearly fifty years ago. The following article, edited by Swami Bhaskarananda, is one of his talks given in Honolulu.
You can read the full article here by Swami Sambuddhananda: https://vimokshananda.org/2020/08/08/sri-ramakrishnas-comfortable-assurance/
Editor's note: Swami Subodhananda was not only a disciple of Sri Ramakrishna, but also a spiritually illumined soul. He has experienced God. Therefore his mind had a preponderance of sattva guna. This is why whatever he experienced in his dream was nothing but the truth.