I will go wid - *Wrightia antidysenterica* ( Apocynaceae ).
Madhuri ji only one link--blog ( http://gardentenders.com/members/sharad/blog/2130 ) identifies dis plant as - Shrilankan tagar / *Tabernaemontana citrifolia*. Most of the info n pics depicts srilankan tagar differently. Such as- http://herbaria.plants.ox.ac.uk/vfh/image/index.php?item=1686&; Regards Neha Singh --
