Hi aaditya!
I agree with libdroidman, you really should consider to use a transistor, so you can control the fan speed using a PWM signal.
The 2N2222 is a great one as it can drive up to 1A.
You can find this transistor in this $3 transistor kit: https://www.ebay.com/itm/153247367412
This tutorial is ideal for a start: https://www.instructables.com/id/PWM-Regulated-Fan-Based-on-CPU-Temperature-for-Ras/