So how many Regiments in a Battal?

A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel. Several battalions are grouped to form a regiment or a brigade.
The nomenclature varies by nationality and by branch of arms, for instance, some armies organize their infantry into battalions, but call battalion-sized cavalry, reconnaissance, or tank units a squadron or a regiment instead. There may even be subtle distinctions within a nation's branches of arms, such as a distinction between a tank battalion and an armored squadron, depending on how the unit's operational role is perceived to fit into the army's historical organization.
A battalion is generally the smallest military unit capable of independent operations (i.e., not attached to a higher command), although many armies have smaller units that are self-sustaining. The battalion is usually part of a regiment, group or a brigade, depending on the organizational model used by that service. The bulk of a battalion will ordinarily be homogeneous with respect to type (e.g., an infantry battalion or a tank battalion), although there are many exceptions. Every battalion will also include some sort of combat service support, typically organized within a combat support company.

A United States Marine Corps battalion includes the battalion headquarters, consisting of the commanding officer (usually a lieutenant colonel, sometimes a colonel), an executive officer (the second-in-command, usually a major), the sergeant major, and the executive staff (S-1 through S-8). The battalion headquarters is supported by a Headquarters and Service Company (Battery). A battalion usually contains 2–5 organic companies (batteries in the artillery), with a total of 500 to 1,200 marines in the battalion. A regiment consists of a regimental headquarters, a headquarters company (or battery), and two to five organic battalions (Marine infantry regiments – three battalions of infantry; Marine artillery regiments – three to five battalions of artillery; Marine combat logistics regiments – two or more combat logistics battalions).

In the U.S. Marine Corps, an infantry or rifle battalion typically consists of a Headquarters and Service Company (H&S Co.), three rifle, or line, companies (designated alphabetically A through M depending upon which battalion of the parent regiment to which they are attached) and a weapons company. Weapons companies do not receive a letter designation. Marine infantry regiments use battalion and company designations as described above under World War II, with company letters D, H, and M not normally used but rather held in "reserve" for use in augmenting a fourth rifle company into each battalion as needed.