The 11th letter stands for year and 12th letter is for month. In your VIN, these are "F" and "J".
F means 2015.
See the below link (Page 13) for Month. In this link, in the image provided at the end of article, you will see 2005-2012 VIN months and they have mentioned that cycle repeats every 4 years. For F (2015), you should see third year in image (i.e. 2007 VIN data) as the next similar series would be for 2013-2016. According to that, month "J" is September.
I hope you understood.
https://www.team-bhp.com/advice/find-your-cars-date-manufacture-vin