Help with IF formula

Hello all,

I've been struggling to write an IF formula for my query below and was wondering if anyone could help. Is it even possible with an IF formula?

I have the data in the screenshot below and I'm trying to create an IF formula in column R based on the following conditions...

If M4 >=0.1 - Tier 3
If M4 >=0.01 + L4 = "#" - Tier 2
If M4 >0.01 + L4 = "<" - Tier 2
If M4 <=0.01 + L4 = "<" - Tier 1

If M4 <0.01 + L4 = "#" - Tier 1

I hope that makes sense. Thank you in advance!