See didn't indulge in promoting any sexual activity further keep license of the premises.

You should not carryout any other a activities other than spa activities inside the centre.

Should  not make use of reference of your customers with any other for any purpose other than of purely social and personal nature. 

Keep proper records of your daily customer. 

Get customer signature at the end of service. 

decide whether you want to operate as a sole proprietorship, limited liability company,  or partnership 

2) you need licence under shop and establishment act of your state 

3)registration under GST if turnover is exceeding Rs 20 lakhs 

4) tools and equipment must be sanitized or boiled to remove bacteria after each use. Other regulations include the use of clean towels, sanitized work stations and properly identifying stored liquids with labels.

You can very well work safely without getting involved in illegal activities of prostitution in spa. All livenses should be renewed periodically

Stay away from illegal activities hire only professionals for spa don't use closed rooms for massage etc. 

In India unfortunately the Spa and Wellness Industry is highly unorganized.Currently there aren't any licenses required to start a Spa business in India. You can take the Shop and Establishment License. 

Problem on what kind ? unwarranted police raid or customer rowdiness  ?

If you are facing problem by police then you cannot do anything except to approach court seeking an order of injunction against the police for this but that will take a long process in the meantime the police, to take revenge may continue to torture you.

If you are facing other problems then you can approach police seeking protection.