New member to Community

I am from Mumbai. I had just enrolled for IOT course.
I don’t have any kit with me at present. If i buy MEGA kit will it be OK or i have to purchase UNO kit ?
Please guide where from can i get it in Mumbai at reasonable cost and the reliable one.
During the lecture, it was mentioned that the AVR microcontroller can be replaced in UNO kit, but it has to be loaded with bootloader. Where from we can get the bootloader program. Is it available in Arduino IDE ?
I also want to know whether we can program Atmel 89C51 or 89C52 microcontroller in Arduino Kit with using external programmer ?
Please clear my doubt.

If you are a beginner in IoT, then Arduino Uno would be the best for you, you may not require MEGA kit. You can program the onboarded microcontroller on the Arduino Uno , however it is not recommended to do so as a beginner.