Wa alaykum salam,
Sister, if (i) acting did not involve doing anything impermissible (e.g. hugging people of the opposite gender, dancing to music etc.) and (ii) the content of the film or drama as a whole did not include anything impermissible then it
wouldn't be wrong.
In the case you described, it would be haram. Your parents are doing a good thing by guiding you away from this profession.
Shirk is one of the biggest of sins. If you play a Hindu on-screen you would need to worship idols as part of your role or things of such nature which would be undoubtedly wrong even if you don't believe in it. You may say your intention is not to worship but you should feel repulsed yourself for even uttering such stuff. Imaan/faith is an extremely important thing. This life is a test and the test should not be taken lightly. If someone dies without imaan, they will never be admitted into paradise and they will be punished in hell for eternity. For someone to worship idols in real life is shirk and that person has no iman. As a Muslim, knowing the importance of imaan, you should never even desire to come close to uttering words of shirk, even as a joke/acting. Imagine when you are in the moment of acting and saying something that has shirk (e.g. 'hey Ram') and Allah were to ordain that your soul be taken at that precise moment?
Another matter altogether is the issue of modesty. As Muslims we need to abstain from immoral behaviour such as touching, hugging, kissing, flirting with, being alone with members of the opposite gender. Obviously, there will be some kind of romantic elements involved in acting that would be unavoidable.
Hijab is also something that you would need to take into account. You can't remove it just for the sake of acting and nobody is going to give you roles purely that involve hijab wearing person. We know that wearing make-up outside is haraam too but obviously you'd need to dress up and look glamorous on TV so that's another problem. Remember, you as an actress don't get to choose what you do, you get told what to do otherwise you're fired. So, even if you don't want to do such things you may be pressured into it and if you do it a few times, it will become normal for you and you'd lose the sense of guilt and shame of the sin.
Also, realise that even in joking some matters are considered seriously in Islam. E.g. if a man says 'I divorce you' as a joke or as part of acting to his wife, it is considered a valid divorce and people can even unintentionally get married if there is a proposal and acceptance in front of two male witnesses. So, don't take this lightly in any way shape or form please sister.
Simply put, there is too much wrong involved for it to be a profession for a Muslim sister to get into. Remember also that if you make one video, it's always going to be there on the internet and even if you later on realise your mistakes, you can never remove it and undo.
I think, sister, you need to be more careful and not let your current passion for acting get into the way of your relationship with Allah and your love of Islam and desire to be a good Muslim. There is a hadith which says to the effect: Whoever gives up something for the sake of Allah, Allah will compensate him with something better than it. Keep that in mind. :)
I know that I won't do anything against islam inshallah
Sister, just want to touch on this point. Allah has made us all inclined toward sinning, nobody is perfect and nobody can say with certainty that they won't do anything against Islam. So, don't take your current pure thinking for granted. Shaytan is flowing through our veins and he is devious, cunning and knows how to play people into committing sin.