Can you please guide me through the integrations Steps and Prerequisites for Integrating AEM 6.3 with Adobe Target via Adobe Launch . Primarily am looking for very simple POC to integrate Target in a sample page on we retail website to change a title based on the browser .
1) Is there any option to integrate Target Directly with AEM without DTM or Adobe Launch
2) If I have target account , will I be able to complete this POC with my local author instance or it can be implemented only on public hosted domain
you can find in  documentation which explain how to configure AEM with Adobe Target.
Regarding your questions:
2) You can complete your poc also in your local environment. The only requirement is to have the Adobe Target and Adobe Launch configured correctly to allow your localhost enviroment
3) No other way, you can do this in localhost and then try to use a test server if you have one environment that you can use for test.
Adobe Launch requires an IMS configuration, so it can be used to set up AEM to Launch integration via Adobe IO. Only AEM >=6.4 has an IMS integration. A very detailed step-by-step integration of AEM & Launch integration can be found here: Integrate Launch by Adobe
You still can deploy Launch asynchronously on the AEM Site.
From Launch, click the Install icon for the Production environment to trigger the Web Install Instructions dialog box:
Copy embed code and add into your site's template. For example, for We.Retail it will be injected into /apps/weretail/components/structurecustomheaderlibs.html file.