entity framework 6 mysql rowversion

First of all, if you are using automatic migration I think that the property attributes are not enough to create the right field type.
Here https://dev.mysql.com/doc/refman/5.5/en/timestamp-initialization.html there are the syntax that EF provider should generate to create a timestamp that is automatically generated/updated.

After creating the right field type you could do 2 tries:

-Mark the field as Timestamp

[Timestamp]
public DateTime TimeStamp { get; set; }

I don't think that EF needs that a Timestamp field is byte[]. Timestamp should only mean that is database generated field and that the optimistic concurrency use that field (i.e. update queries contains a where on the keys of the record to update and this field). But often EF does not work as I think...

-Mark the field as generated by database and as a field to use to check for optimistic concurrency exceptions

[ConcurrencyCheck]
[DatabaseGenerated(DatabaseGeneratedOption.Computed)]
public DateTime TimeStamp { get; set; }