Add margin programmatically to RelativeLayout

Got solution.

When you are using RelativeLayout inside LinearLayout, you need to use LinearLayout.LayoutParams instead of RelativeLayout.LayoutParams.

So replace your following code...

RelativeLayout.LayoutParams relativeParams = (RelativeLayout.LayoutParams)relativeLayout.getLayoutParams();
relativeParams.setMargins(0, 80, 0, 0);  // left, top, right, bottom
relativeLayout.setLayoutParams(relativeParams);

with...

// CODE FOR ADD MARGINS
LinearLayout.LayoutParams linearParams = new LinearLayout.LayoutParams(
        new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT));
linearParams.setMargins(0, 80, 0, 0);
relativeLayout.setLayoutParams(linearParams);
relativeLayout.requestLayout();

You can use setMargins (int left, int top, int right, int bottom).

Try like this..

//CODE FOR ADD MARGINS
    RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    relativeParams.setMargins(0, 80, 0, 0);
    relativeLayout.setLayoutParams(relativeParams);

Layout params should be set with resp to parentLayout .. in this case its LinearLayout as rightly pointed by @ChintanRathod, so

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);

will do the trick..

Be aware that you are using a relative layout inside a linear layout so you should use LinearLayout.LayoutParams

I would replace this :

        //RELATIVE LAYOUT
        RelativeLayout relativeLayout = new RelativeLayout(this);
        relativeLayout.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,
                RelativeLayout.LayoutParams.FILL_PARENT));
        relativeLayout.setBackgroundColor(getResources().getColor(R.color.grayColor));

        //CODE FOR ADD MARGINS
        RelativeLayout.LayoutParams relativeParams = (RelativeLayout.LayoutParams)relativeLayout.getLayoutParams();
        relativeParams.topMargin=80;
        relativeLayout.setLayoutParams(relativeParams);

by this :

        //RELATIVE LAYOUT WITH PROPER LAYOUT PARAMS TO ADD MARGINS
        RelativeLayout relativeLayout = new RelativeLayout(this);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        params.setMargins(0, 80, 0, 0);
        relativeLayout.setLayoutParams(params);
        relativeLayout.setBackgroundColor(getResources().getColor(R.color.grayColor));

Note also that you should use WRAP_CONTENT as height configuration for children in a vertical linearLayout. ( in FILL_PARENT or MATCH_PARENT mode it will fill the parent without leaving space for the other children)