How to check the if condition in Salesforce Visualforce page?

Assign the variable in your apex class and use that variable using below like visualforce page.

Ex1:

<apex:outputPanel id="ref3" style="{!IF((masterLookupType == 'Contacts List'), '', 'display:none')}" >
<apex:inputField value="{!t.Parentid}"></apex:inputField>
</apex:outputPanel>

 Ex2:

<div style="{!IF((enableUATTab),'','display:none')}" >
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</div>

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