Hay consenso sobre la táctica.

Hay is the impersonal form of haber, and in this kind of sentence it means there is / there are.

So:

• Hay consenso = There is consensus
• Hay problemas = There are problems

A few useful contrasts:

• es describes what something is
• está says where something is or what state it is in
• tiene means has

So Hay consenso sobre la táctica is not saying what consensus is, where it is, or who has it. It is simply saying that consensus exists.

Also, in the present tense, hay is used for both singular and plural:

• Hay un problema
• Hay dos problemas

In Spanish, after hay, a noun often appears without an article when you are talking about the existence of something in a general or abstract way.

So:

• Hay consenso = there is consensus
• Hay interés = there is interest
• Hay paciencia = there is patience

If you say hay un consenso, that is possible too, but it sounds a bit more like there is a consensus as a specific, identifiable one.
Without the article, hay consenso feels more natural and general.

Here sobre means about, regarding, or on.

So:

• consenso sobre la táctica = consensus about/regarding the tactic

This is a very common use of sobre in Spanish when talking about a topic.

Other possible expressions exist, such as:

• acerca de
• respecto a
• en torno a

But sobre is very normal and straightforward here.

Spanish often uses the definite article more than English does. Here la táctica suggests a specific tactic that both speaker and listener already know about.

So:

• la táctica = the tactic

If you removed the article and said sobre táctica, it would usually sound unnatural in this sentence.

Spanish commonly uses articles with nouns when referring to something specific or already understood from context:

• el problema
• la idea
• la estrategia

Yes, consenso is a masculine noun: el consenso.

You can see that in other sentences:

• El consenso es importante.
• No existe el consenso necesario.

In your sentence, the article is missing not because the noun is not masculine, but because after hay, Spanish often leaves out the article with abstract nouns:

• Hay consenso
• Hay esperanza
• Hay tensión

So the noun still has gender, but the article is simply not being used in this structure.

Táctica has a written accent because it is stressed on the third-to-last syllable: TÁC-ti-ca.

Words stressed on the third-to-last syllable are called esdrújulas, and in Spanish they always take a written accent.

So:

• táctica
• música
• teléfono
• rápido

That accent mark tells you the stress clearly.

A simple pronunciation guide is:

Ay kon-SEN-so SO-bre la TAK-ti-ka

A few points:

• hay sounds like English eye
• consenso is stressed on -sen-
• sobre is stressed on so-
• táctica is stressed on tác-

In standard Spain Spanish, the c in consenso before e is pronounced like the th in thin:

• roughly: kon-THEN-so

In much of Latin America, it would sound more like:

• kon-SEN-so

Both are correct in their own varieties; for Spain, kon-THEN-so is the expected pronunciation.

Yes, absolutely.

• Hay consenso sobre la táctica = very natural, neutral, everyday
• Existe consenso sobre la táctica = also correct, but a bit more formal or more written in tone

Both mean essentially the same thing.
In ordinary speech, hay is usually the more common choice.

They are related, but not always identical.

• consenso = consensus, broad shared agreement among a group
• acuerdo = agreement, which can also mean a deal, arrangement, or specific agreement between people

So in this sentence, consenso is a good choice because it suggests that people generally agree about the tactic.

Compare:

• Hay consenso sobre la táctica.
  There is broad agreement about the tactic.

• Hay un acuerdo sobre la táctica.
  There is an agreement about the tactic.

The second can sound a bit more specific or formal, depending on context.