My target audience for my thriller

What is the target audience & rating for my film? : For my movie, I have decided to do a target audience of both genders, however the age groups between ideally 15 - 35, thus meaning the rating for my overall film would be a 15. Despite my movie being a 15, the opening sequence however on its own, would most likely be a PG 13, as it doesn't make all the requirements for it to be a 15 just within the sequence.

How do I know thrillers in general have this target audience? : I know that thrillers in general have a target audience from about young adults to middle aged adults. I can confirm this by the fact that the majority of thrillers in general, have a rating being a 15, 18, or 'R', I know this because I researched thriller films and looked at the rating the films got. To add on to that, the context of thriller films tend to be very adult based, including blood, violence, taboo/explicit language and also sometimes sexual scenes etc. Which evidently would not be appropriate for younger people. To add on to that, some sub-genre's of thrillers require heavy intellectual thinking such as psychological thrillers ('Shutter Island') which simply wouldn't be appropriate for younger people as it a 'mind-play' type of film.

Why have I given my film the rating 15? :

The image above shows the official BBFC classification/definition on what makes a 15. Knowing the context of my film (which if you want to define it - is a crime kidnapping film) it would be a 15. This is because it would include strong violence and frequent strong language (evidently of the kidnappers and family members burst's of outrage), although it will not have portrayals of sexual activity there will be references to sexual violence, for example, a mothers fear of what the kidnappers could be doing to her young daughter. To add on to that, where the kidnapping takes place in my film is Colombia, which is a Latin country, and this links up to discriminatory language because the family who's child is kidnapped are a different ethnicity from the majority Latinos living in Colombia, so out of rage & shock prejudiced comments would be made. If I plan my film/opening to be hard-hitting and effective, I want to make it realistic, therefore, realistically, people wouldn't act in a very kind, non-judgmental way when something potentially life-threatening has happened to someone close to them in the hands of strangers.