HI DiNaV,
You should try in OID if your EE has no hope. OID is also good and if your EE is taking more than normal time to get nomination (I see some of candidates not hearing from SINP - EE since 4+ months) then it is worth trying to be on safe side.
Their post-nomination approx processing time is 16 months. They have clearly mentioned that the time shown is based on application processed recently. It could be different.
For example in my case they could have taken 6 months to process the OID but they did in 22 days. So, we never know what is going to happen with processing.
And after all, there is no harm applying in both and once any one of them is started getting near to result, withdraw one of them. That's the best gamble.
I hope this helps.
Thanks,
Parth