Answer: Radhey Radhey,This is a very big question, and to answer it, you will have to understand carefully the basics of the devotional philosophy. In order to correctly guide you, my best recommendation is for you to read Prem Ras Siddhant by Jagadguru Shree Kripalu Ji Maharaj. This book will give you a proper knowledge of the basic concepts of Hinduism, and then the answer to these questions will become obvious to you. Nikhilanand Bhaiya

Answer: Radhey Radhey,  The topic of Radha Rani is one of the deepest and most difficult to understand. For a brief overview, I would recommend the following 2 minute video: https://youtu.be/lokw_BxmlcI.
 For a more in depth understanding, please see the two part lecture by Jagadguru Shree Kripalu Ji Maharaj: https://youtu.be/afbE-kMEwTI. For your brief understanding, I would say that Radha Rani is supreme brahm. She is one with Shree Krishna. She is His female form; or He is Radha's male form.

 

Answer: Who is Radha Rani? We chant her name every day, Radhey Krishn or Radha Krishn during ‘naam-sankeertan.'Radha and Krishn both took avatar around 5000 years ago, in a place called Braj in India, where they spent their time doing leelas, walking with their lotus feet on this very earth. Even today, if you go to the Braj district, in towns like Nandagaon and Gokul, where Shree Krishn grew up, and in towns like Vrindaban, Mathura, Barsana, and Govardhan, where they performed several leelas - in all of these places everybody still greets you with with the name of God, ‘Radhey Radhey.’  Everybody says Jai Shree Radhey. Even if you want someone to move out of your way, you’ll say Radhey Radhey to get their attention!  What is the importance of Shree Radhey? Who is Radha Rani? Simply put (Ye Yam Radha Yasch Krishan),Vedas tell us that Radha is Krishn. Shree Krishn is purnatam purushottam brahm.Brahm means absolute supreme God. His own self is Radha. He Himself appears as male form Shree Krishn and female form as Radha Rani.  You can say that Radha herself has become Shree Krishn, or Shree Krishn Himself has become Radha.They are not two separate personalities. They are one and the same. One supreme Divine power appearing in two forms.Yayam Radha Yasch Krishno……Vedas tell us that in order to do playful leelas, to reveal those playful past times, Radha Krishn although being eternally one, they eternally exist in two forms. One Divine personality in two forms.Shree Radha Rani is supreme Goddess. She herself is Shree Krishn. This is the easiest way to understand who Shree Radha is.Radhey Radhey!Please also see a short Youtube video by Swami Nikhilanand Ji on the question "Who is Radha?" .   

Answer: Jagadguru Shree Kripalu Ji Maharaj teaches that Radha Krishna have unlimited Divine names, and they are all equal to each other and eternal. Thus we can repeat any name that we prefer, and we will get the same benefit. But please keep in mind that the power of Their Divine names remains dormant unless we take Their names with love and faith. If we remember that Radha Krishna are fully present in each of Their names, and that Their name is another form of Them, then we will begin to receive the true benefit of the name - the power of the name will be revealed in our heart, and we will begin to experience the bliss of the Divine name. It is most important to picture the form of Radha Krishna as we repeat Their names - that way our mind will be attached to the one Whose name we are taking (this is called roop dhyan).