k so basically the show started off with the older tani (anupriya), who's a famous singer in Calcutta, coming to a mental asylum to meet the older anurag (harshad). It is shown tht anurag is mentally unstable & he doesnt remember anything. Tani is actually anurag's wife & the whole thing goes to flashbak 10 years bak when they were 14 & 15 year old. The flashbak shows the younger anurag & tani who r best friends & are married by their families at that young age for sum reason or secret. Their marriage is hidden, only their family knws bout it. Then it goes bak to older onu & older tani scene where tani tries to make anurag remember all the stuffs they did when they were small. Then it goes bak to the flashbak part again where more things r getting revealed & probably will show how onu & tani fell in love or how they got separated.
Hope tht helped. Please use the helpdesk next time hun :)