Finally figured this out.

-(NSString*)chartView:(IGChartView*)chartView labelForAxis:(IGAxis*)axis withItem:(NSObject*)item

was returning nil for the newly added axis on the right!

Thanks for all the help.

Okay i see the same in a test app. Now i need to go figure why it does not work on the production app.

This is what I get. Did you try the code snippet I posted or used the axis property setting in your app?
Can you see what framework version and build number you're using?

-Max 

Now I see a big empty space on the right. the y-axis labels are still not visible. 

Send me the screenshot of the chart that the above code produces. 

You just have to set the labelsLocation property on the y axis to OutsideRight and you'll see the labels on the right side.

    NSArray *data = @[@5, @6, @3];
    NSArray *openValues = @[@5, @16, @15,];
    NSArray *closeValues = @[@15, @6, @23];
    NSArray *highValues = @[@20, @20, @29];
    NSArray *lowValues = @[@1, @0, @5];

    _chart = [[IGChartView alloc]initWithFrame:self.view.frame];
    _categoryHelper = [[IGCategorySeriesDataSourceHelper alloc]initWithValues:data];
    _ohlcHelper = [[IGOHLCSeriesDataSourceHelper alloc]initWithOpenValues:openValues highValues:highValues lowValues:lowValues andCloseValues:closeValues];   

    [_chart addSeriesForType:[IGSplineSeries class] usingKey:@"series" withDataSource:_categoryHelper firstAxisKey:@"x" secondAxisKey:@"y"];

    [_chart addSeriesForType:[IGRelativeStrengthIndexIndicator class] usingKey:@"rsi" withDataSource:_ohlcHelper firstAxisKey:@"x" secondAxisKey:@"y2"];

    IGNumericYAxis *y = [_chart findAxisByKey:@"y"];
    y.labelsLocation = IGAxisLabelsLocationOutsideRight;

    [self.view addSubview:_chart];