I think that your ID is correct, but I can't say which one either. It appears that your plant has glued on top dressing. Is this correct? If so, it is best to remove this solid cap in order to allow more efficient watering and aeration. Are you able to move this tree outdoors during summer?
There is a thin layer of small stones on top of the soil & yeah I will be putting outside in the summer. The tag that was with it read Serissa foetida, but all the pictures I've seen don't match. Do you think it could be possible.
I don't grow Serissa but it does not seem like it to me either. Are the topdressing stones glued together in a mass or are they loose? If they are loose, they can stay, otherwise remove the mass.