What steps need to be followed if contract employees, as well as company employees, are going on strike suddenly?

Dear All, Kindly guide me on what steps need to be followed if contract employees, as well as company employees, are going on strike suddenly?

You can adopt the formula of "No work No Pay" if they resort to strike in a peaceful manner.
If you anticipate any untoward incidents that may be likely to be happened, inform Police/District Admn/Labour Deptt.

Have they served notice of strike? Have you convened any meeting? If so, what was the outcome?

You should provide all details if you want a proper answer.
Just giving a one line, is like asking an interview question or you can simply look at a text book. If you want a proper answer without people just guessing the circumstances, you better give the details

Are the issues/demands of the regular workmen and contract labourers the same. At best don't mix the two, make the contractors a necessary party in dealing with the contract labour matters.
You shall involve the Labour officials in your local area to start conciliation proceedings. As per ID Act 1947, a strike cannot commence or continue while the conciliation proceedings are on.
More advice can be rendered only after more details are known.