Specification of i3 9th generation

[Amit922]

I3 9th generation processor can support 12gb ram

[AlHill]

What are you asking, and what is the model number of the processor?

Doc (not an Intel employee or contractor)
[Maybe Windows 12 will be better]

[Amit922]

Now I am using 8gb ram in it can i upgrade it to 12gb

[AlHill]

Again, what is your processor model number?  i3 9thgen is not enough.

Doc (not an Intel employee or contractor)
[Maybe Windows 12 will be better]

[Amit922]

Intel(R) Core(TM) i3-9100F CPU @ 3.60GHz 3.60 GHz

[AlHill]

This is your processor:

https://ark.intel.com/content/www/us/en/ark/products/190886/intel-core-i39100f-processor-6m-cache-up-to-4-20-ghz.html

It can support upto 64GB of memory.

What is important is what your motherboard supports.  Check the memory specifactions for their board.

Doc (not an Intel employee or contractor)
[Maybe Windows 12 will be better]