What type entry connector do I use at meter to seal 4/0 4/0 4/0 2/0 ser coming from utility. I'm not using coduit and the wire is not flat

Is this a typical dwelling unit service?
If so, why do you have a four wire cable on the line side
Of the demand meter?

I bought for meter to service panel not going to use 4th wire on that side

... so from the meter to your panel you're running 4 wire?
I"m a little confused as to why you're running SER from the meter to your panel?
Unless the main circuit breaker is also located at the meter you only need SEU or
3-wire...
Of course the answer to your original question is "yes", they make SER connectors
For 4-wire service cable... but I would like to know why this sounds unusual.

Please let me know...

You cannot simply cut off one wire.
You need to use the correct SEU cable with a rubber connector.