Just a doubt

Hello. This is my first time in the FF forum. Can I write Fanfiction on episodic series like Pyaar Tune Kya Kiya, Laal Ishq, Gumrah, Yeh hai Aashiqui, Confessions of an Indian teenager? I was thinking of writing a PTKK FF? Which PTKK jodi would you like to see in FF? Please let me know in the comments.