Garcinia lanceifolia

Was it wild or cultivated? 

The grower says he brought a seedling from forest and planted in his house.
The colour and texture of the fruit are not matching with those of Garcinia homobroniana/ Garcinia indica/ Garcinia parvifolia. It is an Indian species rarely found, I think.
Over a period of time my friend collected photos of flower, unripe fruit and ripe fruit.
Is there any possibility that it could be Garcinia affinis. In Assamese it is also called Mahi thekera but the name indicates 2-3 Garcinia species like Garcinia anomala,Garcinia xanthochymus etc and fruits of none is red in colour. The red is not exactly red, something is different.

It is Garcinia lanceifolia Roxb. 

References:

Catalogue of Life  The Plant List Ver.1.1
 IPNI  IBIS Flora  Plant illustrations  Garcinia lanceifolia Roxb; An Endemic Medicinal Plant of Assam Relieves Pain and Delays Nociceptive Response: An Assay for Its Analgesic and Anti-inflammatory Activity