Formation of association for legal status

Sir, 

Humbly placing following concerns as below;

We undertake contractual work from Public Sector Companies. We would like to form an association of ours in order to have a legal status. We want to know the procedues and under which regulation the same can be registered. Also would like to avoid cumbersome procedures as complaince to State and Central administration.

We shall be thankful to your Esteemed Forum for the valuable guidence. 

Thanking All Experts with sincere appreciation.