How about calender spread in future trading ? does that manage risk ? If so when to enter and when to exit ? how the profit is taken .....I am not clear with this.
Calendar spreads incur basis risk. Nonetheless, they can be used to hedge your long position by selling the outer contract. But, really, this is just taking no directional position at all and mostly positioning on the basis of deviation of fair values embedded into each contract.
If you aren't going to use options and are concerned for a market gap and want to remain open and at risk in a directional play, this doesn't work.
Given the restrictions you are putting on this, the hedge you are looking for is a basket of (generally linear) assets whose value rises in the event of an economic shock but which ideally does it's own thing otherwise. This is a kind of protection option but it is a 'jelly hedge' because the instruments are not directly related to equity index futures. They are correlated with them in some way, but the correlation is not assured.
If you are wanting to go down this route, I'll step off and let others give you guidance about basket formation/composition/hedge implementation. I'd be curious to learn how others approach this, for one thing. But, from the questions you are asking, I would raise a caution flag about undertaking this activity unless you are confident that you can assess the risks. A basket jelly hedge over an equity index is not exactly run of the mill. This stuff can blow you up. It has blown up entities staffed by very smart and experienced people.
Further to SkyQuake's views, IG Markets does not offer guaranteed trailing stops but they do offer guaranteed stops. Whack one of these on, for an insurance premium, and your stop is guaranteed even if the market gaps overnight. The drawback is that this risk limit must be determined at initiation. Although this actually embeds an option into your trade, just ignore that I even wrote this and think of it as a cast iron limit that holds even in an overnight/weekend correction or other non-trading period.
If you don't want to do any of the above, you can't take the risk you had in mind. Your choices come down to reducing it or removing it.