I noticed that my daughter was really interested in boy stuffs like toy cars , robots and toy guns . Is that normal and is it okay to let her play those ? Photo source : (https://www.radiozamaneh.com/u/wp-content/uploads/2015/02/girl-playing-with-cars.jpg)

Yes of course. I grew up playing with robots instead of Barbie dolls and I guess it was just fine. I think it's time to veer away from the typical robots for boys, dolls for girls stereotype. I suggest though you can start giving your child gender neutral toys like animal toys :)