There is no one answer to this question. It depends on the module orientation (portrait or landscape), the location of the TS4, the desired cable management, etc. The standard TS4-A-2F product was designed for PV modules with conventional j-boxes and lead length. See below.
For any other PV module type, especially the split j-box PV modules that are becoming more popular (see below), it is very important to check the cable lengths. Some newer modules are being made with very short cables. See below for an example of cabling TS4-A-2F with modules in landscape. That is usually the worst case for cable length. The dimensions in the illustration below show the TS4-A-2F standard input cable lengths in green (120mm, 200mm) and the length of the example PV Module cables in white (1245mm, 1233mm, etc) needed to reach the TS4-A-2F in this location. The TS4-A-2F output cables (2200mm) are shown in yellow.
It is important to check both the input cables to the TS4 (green) and the TS4 output cables (yellow). The TS4 lead lengths can be seen on the data sheet. Also, there is a version of the TS4-A-2F with longer leads than the standard product. Please check with Tigo sales for ordering information.