user103373: Good day.
I have a slight issue! A friend of mine has imported a few wallets to his main wallet. All the imported wallets has "Non Spendable Bitcoin" in them ranging from $2-$45k respectively. Is there any way i can retrieve them via finding the private keys for them to make the btc coins spendable again? Any help or advice will be highly appreciated.

user61384: Impossible unless you have the private key belonging to the adress.
Your friend didn't import a few "wallets", he imported a few adresses, which makes his wallet a "Watch-Only wallet" (for the adresses that were imported.)

Is there any way i can retrieve them via finding the private keys for them to make the btc coins spendable again?

Again, if you only have a public key, master public key, or adress format, the answer is no. 
If you have a seed / private key from which the (imported) address xpub/public key was originally derived from, then yes, you could recover his funds.
Edit: I feel like we're missing a whole lot of context here: Did your friend buy these "wallets"? If so- he most likely got scammed.

103373: <p>Good day.</p>

<p>I have a slight issue! A friend of mine has imported a few wallets to his main wallet. All the imported wallets has "Non Spendable Bitcoin" in them ranging from $2-$45k respectively. Is there any way i can retrieve them via finding the private keys for them to make the btc coins spendable again? Any help or advice will be highly appreciated.</p>
 61384: <p>Impossible unless you have the private key belonging to the adress.</p>

<p>Your friend didn't import a few "wallets", he imported a few adresses, which makes his wallet a "<a href="https://bitcoin.org/en/glossary/watch-only-address" rel="nofollow noreferrer">Watch-Only</a> wallet" (for the adresses that were imported.)</p>

<blockquote>
  <p>Is there any way i can retrieve them via finding the private keys for them to make the btc coins spendable again?</p>
</blockquote>

<p>Again, if you only have a public key, master public key, or adress format, the answer is no. </p>

<p>If you have a seed / private key from which the (imported) address xpub/public key was originally derived from, then yes, you could recover his funds.</p>

<p>Edit: I feel like we're missing a whole lot of context here: Did your friend buy these "wallets"? If so- he most likely got scammed.</p>
