To even begin to give dosing advice for this you would have to know how much is on each tab...generally these days thats betweem 500ug-1000ug but I've also seen 1500 and 2000ug tabs which is a huge difference. Also you then have to count the factor that sometimes they aare complexed and sometimes are in HCL salt form causing even more discrepancy between what doses work for who.
Honestly you really should just gett rid of them. These NBOMe drugs are so new and each one individually has already killed more people than LSD, 2cb, 2ci, 4-aco-dmt combined an that only took 4 years or so.
That being said something is very wrong with them and how they behave. Ntm people have also died taking less than they have in the past which is a mind-boggling phenomena so until some extensive testing is done in animals working up to humans to try and draw some conclusions (which probably will never happen), Id tread with the most extreme caution. Theyre so damn cheap for a reason....Just because this bottle of wine is 2 dollars, does it really make it worth it to have 10 bottles of shitty wine when you can get 1 or 2 bottles of good wine?
If you just must take it and end up doing it anyway then do your best to figure out what the dose is. Get in touch with whoever you got them from and verify this as well as if it is complexed or is in HCL form, this makes a difference.
Lastly, you should NOT take them orally. Orally means swallowing them like a pill which will have no effect, you must take them sublingually/buccally meaning under your tounge or in your gum. Back when I was doing NBOMes I preferred buccal to sublingual because of the taste but either will work.
Be safe man; a cheap trip isnt worth the very real possibility of complications, even non-fatal ones...
http://www.bluelight.org/vb/threads/679079-25B-NBOMe-warning-bad-trip-non-fatal-overdose-1000ug