Vansh in his past indeed have a relationship with Ragini it could be love. Hence the tattoo. Around the sme time his father dies and Vansh took the reigns to the empire. He was new to the game and Ragini paid the price for it. Vansh's character changed after that (the Vansh we see now) he is ruthless, cunning and unforgiving. He takes care and protects Ragini out of guilt.
Now let's come to the present scenario. Vansh wants to have a relationship with Riddhima but is apprehensive due to his past. This is the reason why he takes one step forward and then two steps back.
According to me you can fall in love many time but you get true love only once. Even Romeo loved Rosaline before he met Juliet. Even Riddhima loved Kabir before she met Vansh.
I think Vansh loved Ragini but Riddhima is his true love and we all know the lengths people go for their love. If Riddhima can go to this extreme for Kabir then just imagine the lengths she would go for Vansh.
I think Riansh is the end game but we are sure in for a rollercoaster ride and I look forward to it.