Can someone please guide me about the following questions:
I'm so confused regarding both of these npm packages.
The Github repo says it all :
A set of tslint rules for static code analysis of Angular TypeScript projects.
So no they're not both dependent on each other. Only Codelyzer relies on TsLint.
And yes you need both of them for your angular projects if you want to lint your code OR you can use only TsLint and set your own rules but it's not too much fun and I'd advise you to use Codelyzer ;)