need to attend university whose I-20 is yet to come, but have another I-20. need to apply visa asap

I have got two admits and have I-20 for one and another is expected to arrive soon…
I want to apply for visa asap with the I-20 i have and then after coming to US, could i join the university (whose I-20 is yet to come) which is in another state…
Is this allowed or would there be difficulties or violation of any policy…

Yes, you can transfer Universities after you arrive in US. Typically, many schools allow you transfer after the first semester…Some of them even allow transfer in the first semester, but you need to be careful.