Good question. i will try my level best to answer this question. i will be happy if it gives you satisfaction. Now we will go to the answer.
your question is this: what is the difference between Tulsidas and Valmiki Ramayana ?
The Ramayana was first written by Valmiki the robber-turned-sage. The story of Rama was narrated to him by Narada. Once he witnessed a bird being killed by a hunter and heard the heart-rending cry of the bird’s mate. He felt the pain and out of this pain he was inspired to write the Ramayana. The date of Valmiki’s Ramayana has bee stated by various sources as between 1500 BC and 500 BC.
Since then the Ramayana has been written in practically each Indian language and several foreign languages. Then there are numerous stage, film and television productions of the Ramayana. Tulsidas writes, “God is limitless and there is no limit to his stories.” In this section we shall be concerned with Valmiki Ramayana and two others. One is Kamba Ramayana written in Tamil in the eleventh century by Kamban. The prescribed text is based on this Valmiki Ramayana.
The other is Rama Charita Manas written by Tulsidas in the sixteenth century. This has been written in an early form of Hindi. We shall consider two episodes from the Ramayana, Ahalya and Vali, which have moral and social repercussions and try to draw conclusions about the changing values in society.
Some versions of the Ramayana differs with the incident about Vali. This incident is one of the most controversial in the Ramayana. Rama is portrayed as the epitome of virtue and moral uprightness. The question then arises why he did not challenge Vali to a face-to-face contest, but chose to kill him from hiding while Vali and Sugreeva were engaged in a duel.
Had anyone else performed such an act he would surely have been branded a coward. Vali puts this question to Rama in Valmiki and Kamban Ramayana. Again Tulsidas does not deal with the issue.
Also there are numerous differences between Tulsidas Rāmcaritmānas and Valmiki Ramayana. One example is the scene in which Kaikayi forces her husband to exile Rama. In Tulsi Das it becomes considerably longer and more psychological, with intense characterisation and brilliant similes.
There are some contradictions between Tulsi Rāmacaritamānasa and Valmiki Ramayana. For example, in Valmiki Ramayana in 36th Sarga of Bala Kanda, there is the story of Parvati. In Rāmacaritamānasa, there is the story of Sati testing Rama when he is searching for Sita after she was abducted. Since Parvati is the reincarnation of Sati, Sati should have come first in these stories and Parvati later. However, in these stories Parvati comes first and Sati later.
so, Ramayana was originally written by a sage Valmiki in the Sanskrit language and later on it was translated into other languages in different versions. The main story of the Ramayana is about Lord Rama. In short the Ramayana is based on the true story life of Sri RAM the writer of Ramayan in Hindi is Sant Tulsidas.
The Ramacharitamanas is composed by Tulsidas as Shiva appeared in dream and told him. Sant Tulsidas wrote this on Rama Bhakti alone.
Thanks for the opportunity !!!