I'm planning to do some research. Therefore, Appriciate if you could kindly help me to find out Astronomical datasets.
Have you seen in the news that Google released a brand new Google Dataset Search yesterday. It is a very convenient way to search for datasets, and overall it looks very promising.
Take a look at https://data.nasa.gov/. They got plenty of freely available and even commercially usable datasets in a broad range of fields and topics.
You may find almost all the relevant astronomical catalogs at http://vizier.u-strasbg.fr/viz-bin/VizieR