... TLDs are different but the pronunciations are same. Even the Quickr.com is taken by them too. will this lead to a Legal, Branding problem in future? Can they acquire my site future?
You could try legal questions on Law.SE but it's always best for the lawyer whom helped you set up your company to have checked these sorts of things beforehand.
For the on-topic portion of your question see this page on cybersquatting at the Internet Corporation for Assigned Names and Numbers (ICANN) - they resolve disputes over the rights to domain names.
"If someone has registered a domain name in a generic top-level domain (gTLD) operated under contract with ICANN that you believe may be infringing on your trademark, you may be able to file a Uniform Domain Name Dispute Resolution Policy (UDRP) proceeding against the registrant.
The UDRP provides a mandatory, low-cost administrative procedure primarily to resolve claims of abusive, bad faith domain name registration. In other situations, disputes may need to be resolved by traditional means such as voluntary negotiation and lawsuits.
The UDRP is only available for gTLDs operated under contract with ICANN
A full list of such gTLDs is on ICANN's Registry Listing page. For a list of country code top-level domains (ccTLDs) please refer to the complete list of ccTLDs IANA's Root Zone Database.
It is recommended to seek legal advice before filing a UDRP.
Additional information is on ICANN's webpage for Uniform Domain Name Dispute Resolution Policy.".
There is somewhere that they can file a complaint, sometime after you are discovered you can expect a letter from their lawyer asking you to cease and desist; it's also possible to simply pull the rug out from under you. There's no advantage to your business to be confused with another business, unless that's your purpose; it's always best to be unmistakable, that way if the other company has problems you won't be mistaken for them.