RASALEELA” means “SPIRITUAL UNITY” or Philosophical UNITY among Devotees and DEITY. LORD KRSNA’s followers were called “TATTVAVADIS”. They did not agree with LORD RAMA being DEITY after LORD KRSNA’s appearance on earth. Though both LORD RAMA AND LORD KRSNA were later deemed to be avatars of LORD MAHAVISHNU.

Consider the events around RADHA and KRSNA’s divine relationships. LORD KRSNA was often seen with many GOPIS or Girl devotees during KRSNA’s LIFE TIME.
BUT, WHY RADHA was “NOT” taken as a WIFE by LORD KRSNA?

“TEXT 130
TEXT
'vrajendra-nandana' bali' tanre jane vraja-jana
aisvarya-jnane nahi kona sambandha-manana
SYNONYMS
vrajendra-nandana--the son of Nanda Maharaja, the King of Vrajabhumi; bali'--as; tanre--Him; jane--know; vraja-jana--the inhabitants of Vrajabhumi; aisvarya-jnane--in opulence; nahi--there is not; kona--any; sambandha--relationship; manana--regarding.
TRANSLATION
"The inhabitants of Vrajabhumi know Krsna as the son of Maharaja Nanda, the King of Vrajabhumi, and they consider that they can have no relationship with the Lord in the rasa of opulence”
http://www.harekrsna.com/philosophy/acarya/writings/madhya9.htm

RADHA was from a group of people, who believed in GREED for power, money and hungry for body or sensual pleasures. Though She might have been a great woman, SHE was NOT accepted by “KURU” people as a wife for their LORD KRSNA.
“THEY CONSIDER THAT THEY CAN HAVE NO RELATIONSHIP w the LORD in the Rasa of Opulence”.
Here the Term THEY=KURUS or Radha’s relatives. IT was most likely that Romans barred RADHA from becoming LORD KRSNA’s wife, because LORD KRSNA was from KURU DYNASTY and was dark skinned. Also, LORD KRSNA’s occupation or VARNA was only a yadhava or cowherd.