В этом совете есть толк.

Because в can take different cases depending on the meaning:

• в + accusative = motion into something
  
  • в этот совет = into this council / into this advice (not what is meant here)
• в + prepositional = location or something understood as being in something
  
  • в этом совете = in this advice

In this sentence, the idea is there is sense in this advice, not movement toward it, so Russian uses the prepositional case.

Because after в with the meaning in, the noun goes into the prepositional case.

The noun is:

• nominative: совет
• prepositional: (в) совете

So:

• совет = advice / counsel / council
• в совете = in the advice / in the council

Here этом also matches that same case, so you get:

• в этом совете

Этом is the prepositional singular masculine/neuter form of этот (this).

Since совет is:

• masculine
• singular
• in the prepositional case

the demonstrative has to match it:

• nominative: этот совет
• prepositional: в этом совете

Russian adjectives and words like этот must agree with the noun in gender, number, and case.

Here толк means something like:

• sense
• point
• use
• value
• good practical meaning

So есть толк means there is some sense/use in it.

In this sentence, В этом совете есть толк means that the advice is not pointless — it has value or makes sense.

This is a common Russian expression:

• В этом есть толк. = There’s something to that.
• От этого нет толку. = There’s no use in that.

That is a very common learner question.

Russian usually drops to be in simple statements:

• Он врач. = He is a doctor.

But есть is still used when the meaning is more like there is / there exists / there is present.

So here:

• В этом совете есть толк = There is sense in this advice

This is an existential meaning, not just a simple linking verb.

If you remove есть, the sentence may still be understandable, but есть sounds natural here because it emphasizes the existence of толк.

It can mean either in other contexts, but here it means advice.

Совет has two common meanings:

• advice
• council / board / council body

In this sentence, толк makes it clear that advice is meant:

• В этом совете есть толк = There is sense in this advice

If it meant council, the sentence would sound odd in most contexts.

Because толк is the thing that exists in the sentence.

In the structure где-то есть что-то (there is something somewhere):

• the place or context is often expressed first: в этом совете
• the thing that exists is in the nominative: толк

So literally the structure is:

• In this advice there is sense.

That is why толк stays in its basic dictionary form.

Yes. Russian word order is flexible, but changing it changes the emphasis.

• В этом совете есть толк. = neutral, natural
• Есть толк в этом совете. = slightly more emphasis on there is sense
• Толк в этом совете есть. = stronger contrast or emphasis, as if responding to doubt

For a learner, В этом совете есть толк is the safest and most standard version.

It is not completely fixed word-for-word, but it uses a very common pattern:

• В чём-то есть толк. = There is sense in something.
• В этом есть толк. = There’s something to that.
• В твоих словах есть толк. = There’s sense in what you’re saying.

So the phrase есть толк is very common, and this sentence is a normal example of that pattern.

Yes, but the nuance is a bit different.

• смысл = meaning, sense, point
• толк = practical sense, usefulness, value, good effect

Compare:

• В этом есть смысл. = This makes sense.
• В этом есть толк. = There is something useful / sensible in this.

In many situations they are close, but толк often sounds a bit more practical or idiomatic.

It is mostly neutral and very natural Russian.

It is not slang, and it is not especially formal. You could use it in everyday speech, writing, or discussion when you want to say that a suggestion or piece of advice has merit.

It may sound slightly more idiomatic than a very literal learner-style sentence like Этот совет имеет смысл, which is understandable but less natural in many everyday contexts.