The phrase “तो क्या हुआ” in Hindi is similar to the expression “so what if” in English.
मुझे देर तक सोना पसंद है तो क्या हुआ – “So what if I like to sleep late?”
वह थोड़ा सा मोटा है तो क्या हुआ – “So what if he’s a little fat?”
The phrase “तो क्या हुआ” can be used as a retort, like “so what?” in English.