We have the HD Guide that tells you the equivelant grade for each letter:

A+ = 85+
A = 80-84
A- = 74-79
.....
F- = 0-15

I was wondering if somewhere i can see the equivelant grade of OVR letter. Like if a player OVR is graded A- does it mean he is between 700 - 750 or 750 to 800.

I'm not sure if there is a table for that. But you also shouldn't be scouting/ recruiting based off of OVR rating. The potentials aren't factored in. As well as a category like durability (which basically is unimportant) can mislead on the players ability.

it's likely that if overall rating is equal, a player with a durability rating of 2 is better NOW than a player with a durability of 100. Excluding potential.

don't focus on overall rating much

Yes I'm aware of it. I'm trying more to assess how the player fares against the other targets i have in scouting to determine how well he is going to be sought after.

If for example you have a player with overall rating 550 and durability 1, and you stack him against a player with same equal rating except durability is 100, so his overall rating is 649, he is going to be ranked a lot higher and will be a lot more on people's radar and target.

So i'm just trying to get an idea of how the player is assessed with my lvl 4 scouted players.

To be specific, as my D+ prestige school, I'm already know that I won't get the A graded players and i'll be lucky with 1 or 2 B graded players. If i get an idea of where the B-/C+ has it's rating, it'll give me an idea of how reachable he will be

You might get more useful info by trying to understand the range of values possible within the Physical, Defense and Offense groupings. Overall just isn't worth investigating. It doesn't make sense to consider Overall "to determine how well he is going to be sought after" when pretty much everyone understands that Overall doesn't affect how much they will pursue a player and doesn't consider it. If hardly anybody looks at Overall, it simply doesn't affect "how well he is going to be sought after."