Automating bulk appliances

I have 50 bulbs and 50 ceiling fans,I want to automate using openhad bt which hardware is suitable for automating of huge number of appliances ! Can I use raspeberry pi or anyother hardware. Please help me out! Thank you in advance

100 devices is not really a huge number!
A raspberry pi will do just fine!

but raspberry has just 40 pins right

Yes, but you can expand using i2c bus

but how many i2c buses can be connected to raspberry pi ?

An example can be this one.

so all the pins I can connect to relay board ri8?

You can have a maximum of 128 I/O ports using this type of board! Be careful, you will need extra parts for the relays, such as transistors, resistors, etc.
Depending on the physical layout of your installation (cable routing), centralizing 100 circuits in one place can be tedious.

Okay I will be in touch with you till my project works! Thank you in advance