[Solved]-How to add one standalone project into another maven project-eclipse

you can make those projects into two different modules under single project.

project structure:

/test_sample
--/maven-selenium
--/reportng

root pom.xml:

<project xmlns="http://maven.apache.org/pom/4.0.0" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"
        xsi:schemalocation="http://maven.apache.org/pom/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
        <modelversion>4.0.0</modelversion>
        <groupid>com.test.sample</groupid>
        <artifactid>test_sample</artifactid>
        <version>1.0</version>
        <packaging>pom</packaging>

        <modules>
            <module>maven-selenium</module>
            <module>reportng</module>
        </modules>    

    </project>

note: you can also add reportng as a dependency to maven-selenium module as per requirement.