Please go through https://www.citehr.com/344521-buildi...lrker-law.html thread in which you will get some idea about the BOCW Act, Rules and other construction related materials which will be useful to you.
Hope you might have obtained the approval for construction of the factory from the Inspector of Factories. After approval you can start construction of your factory. Once the Manufacturing process is commenced, then automatically the BOCW Act applicability will be ceased and the Factories Act will be applied.
You have to contact with local labour deparment where you can get form for registration if you have awarded construction contract to someone else. 1% of the total cost as labour cess will be deposited by you with the BOCW department. Thanks.